pragma solidity 0.4.23;

// File: zeppelin-solidity/contracts/math/SafeMath.sol

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {
  function mul(uint256 a, uint256 b) internal constant returns (uint256) {
    uint256 c = a * b;
    assert(a == 0 || c / a == b);
    return c;
  }

  function div(uint256 a, uint256 b) internal constant returns (uint256) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return c;
  }

  function sub(uint256 a, uint256 b) internal constant returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  function add(uint256 a, uint256 b) internal constant returns (uint256) {
    uint256 c = a + b;
    assert(c >= a);
    return c;
  }
}

// File: zeppelin-solidity/contracts/token/ERC20Basic.sol

/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/179
 */
contract ERC20Basic {
  uint256 public totalSupply;
  function balanceOf(address who) constant returns (uint256);
  function transfer(address to, uint256 value) returns (bool);
  event Transfer(address indexed from, address indexed to, uint256 value);
}

// File: zeppelin-solidity/contracts/token/BasicToken.sol

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances. 
 */
contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  mapping(address => uint256) balances;

  /**
  * @dev transfer token for a specified address
  * @param _to The address to transfer to.
  * @param _value The amount to be transferred.
  */
  function transfer(address _to, uint256 _value) returns (bool) {
    balances[msg.sender] = balances[msg.sender].sub(_value);
    balances[_to] = balances[_to].add(_value);
    Transfer(msg.sender, _to, _value);
    return true;
  }

  /**
  * @dev Gets the balance of the specified address.
  * @param _owner The address to query the the balance of. 
  * @return An uint256 representing the amount owned by the passed address.
  */
  function balanceOf(address _owner) constant returns (uint256 balance) {
    return balances[_owner];
  }

}

// File: contracts/token/BurnableToken.sol

/**
 * @title Token which could be burned by any holder.
 */
contract BurnableToken is BasicToken {

    event Burn(address indexed from, uint256 amount);

    /**
     * Function to burn msg.sender's tokens.
     *
     * @param _amount amount of tokens to burn
     *
     * @return boolean that indicates if the operation was successful
     */
    function burn(uint256 _amount)
        public
        returns (bool)
    {
        address from = msg.sender;

        require(_amount > 0);
        require(_amount <= balances[from]);

        totalSupply = totalSupply.sub(_amount);
        balances[from] = balances[from].sub(_amount);
        Burn(from, _amount);
        Transfer(from, address(0), _amount);

        return true;
    }
}

// File: zeppelin-solidity/contracts/token/ERC20.sol

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 is ERC20Basic {
  function allowance(address owner, address spender) constant returns (uint256);
  function transferFrom(address from, address to, uint256 value) returns (bool);
  function approve(address spender, uint256 value) returns (bool);
  event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: zeppelin-solidity/contracts/token/StandardToken.sol

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * @dev https://github.com/ethereum/EIPs/issues/20
 * @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is ERC20, BasicToken {

  mapping (address => mapping (address => uint256)) allowed;


  /**
   * @dev Transfer tokens from one address to another
   * @param _from address The address which you want to send tokens from
   * @param _to address The address which you want to transfer to
   * @param _value uint256 the amout of tokens to be transfered
   */
  function transferFrom(address _from, address _to, uint256 _value) returns (bool) {
    var _allowance = allowed[_from][msg.sender];

    // Check is not needed because sub(_allowance, _value) will already throw if this condition is not met
    // require (_value <= _allowance);

    balances[_to] = balances[_to].add(_value);
    balances[_from] = balances[_from].sub(_value);
    allowed[_from][msg.sender] = _allowance.sub(_value);
    Transfer(_from, _to, _value);
    return true;
  }

  /**
   * @dev Aprove the passed address to spend the specified amount of tokens on behalf of msg.sender.
   * @param _spender The address which will spend the funds.
   * @param _value The amount of tokens to be spent.
   */
  function approve(address _spender, uint256 _value) returns (bool) {

    // To change the approve amount you first have to reduce the addresses`
    //  allowance to zero by calling `approve(_spender, 0)` if it is not
    //  already 0 to mitigate the race condition described here:
    //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
    require((_value == 0) || (allowed[msg.sender][_spender] == 0));

    allowed[msg.sender][_spender] = _value;
    Approval(msg.sender, _spender, _value);
    return true;
  }

  /**
   * @dev Function to check the amount of tokens that an owner allowed to a spender.
   * @param _owner address The address which owns the funds.
   * @param _spender address The address which will spend the funds.
   * @return A uint256 specifing the amount of tokens still avaible for the spender.
   */
  function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
    return allowed[_owner][_spender];
  }

}

// File: contracts/token/TokenWithApproveAndCallMethod.sol

/// @title Utility interface for approveAndCall token function.
interface IApprovalRecipient {
    /**
     * @notice Signals that token holder approved spending of tokens and some action should be taken.
     *
     * @param _sender token holder which approved spending of his tokens
     * @param _value amount of tokens approved to be spent
     * @param _extraData any extra data token holder provided to the call
     *
     * @dev warning: implementors should validate sender of this message (it should be the token) and make no further
     *      assumptions unless validated them via ERC20 methods.
     */
    function receiveApproval(address _sender, uint256 _value, bytes _extraData) public;
}


/**
 * @title Mixin adds approveAndCall token function.
 */
contract TokenWithApproveAndCallMethod is StandardToken {

    /**
     * @notice Approves spending tokens and immediately triggers token recipient logic.
     *
     * @param _spender contract which supports IApprovalRecipient and allowed to receive tokens
     * @param _value amount of tokens approved to be spent
     * @param _extraData any extra data which to be provided to the _spender
     *
     * By invoking this utility function token holder could do two things in one transaction: approve spending his
     * tokens and execute some external contract which spends them on token holder's behalf.
     * It can't be known if _spender's invocation succeed or not.
     * This function will throw if approval failed.
     */
    function approveAndCall(address _spender, uint256 _value, bytes _extraData) public {
        require(approve(_spender, _value));
        IApprovalRecipient(_spender).receiveApproval(msg.sender, _value, _extraData);
    }
}

// File: mixbytes-solidity/contracts/ownership/multiowned.sol

// Copyright (C) 2017  MixBytes, LLC

// Licensed under the Apache License, Version 2.0 (the "License").
// You may not use this file except in compliance with the License.

// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND (express or implied).

// Code taken from https://github.com/ethereum/dapp-bin/blob/master/wallet/wallet.sol
// Audit, refactoring and improvements by github.com/Eenae

// @authors:
// Gav Wood <g@ethdev.com>
// inheritable "property" contract that enables methods to be protected by requiring the acquiescence of either a
// single, or, crucially, each of a number of, designated owners.
// usage:
// use modifiers onlyowner (just own owned) or onlymanyowners(hash), whereby the same hash must be provided by
// some number (specified in constructor) of the set of owners (specified in the constructor, modifiable) before the
// interior is executed.

pragma solidity ^0.4.15;


/// note: during any ownership changes all pending operations (waiting for more signatures) are cancelled
// TODO acceptOwnership
contract multiowned {

	// TYPES

    // struct for the status of a pending operation.
    struct MultiOwnedOperationPendingState {
        // count of confirmations needed
        uint yetNeeded;

        // bitmap of confirmations where owner #ownerIndex's decision corresponds to 2**ownerIndex bit
        uint ownersDone;

        // position of this operation key in m_multiOwnedPendingIndex
        uint index;
    }

	// EVENTS

    event Confirmation(address owner, bytes32 operation);
    event Revoke(address owner, bytes32 operation);
    event FinalConfirmation(address owner, bytes32 operation);

    // some others are in the case of an owner changing.
    event OwnerChanged(address oldOwner, address newOwner);
    event OwnerAdded(address newOwner);
    event OwnerRemoved(address oldOwner);

    // the last one is emitted if the required signatures change
    event RequirementChanged(uint newRequirement);

	// MODIFIERS

    // simple single-sig function modifier.
    modifier onlyowner {
        require(isOwner(msg.sender));
        _;
    }
    // multi-sig function modifier: the operation must have an intrinsic hash in order
    // that later attempts can be realised as the same underlying operation and
    // thus count as confirmations.
    modifier onlymanyowners(bytes32 _operation) {
        if (confirmAndCheck(_operation)) {
            _;
        }
        // Even if required number of confirmations has't been collected yet,
        // we can't throw here - because changes to the state have to be preserved.
        // But, confirmAndCheck itself will throw in case sender is not an owner.
    }

    modifier validNumOwners(uint _numOwners) {
        require(_numOwners > 0 && _numOwners <= c_maxOwners);
        _;
    }

    modifier multiOwnedValidRequirement(uint _required, uint _numOwners) {
        require(_required > 0 && _required <= _numOwners);
        _;
    }

    modifier ownerExists(address _address) {
        require(isOwner(_address));
        _;
    }

    modifier ownerDoesNotExist(address _address) {
        require(!isOwner(_address));
        _;
    }

    modifier multiOwnedOperationIsActive(bytes32 _operation) {
        require(isOperationActive(_operation));
        _;
    }

	// METHODS

    // constructor is given number of sigs required to do protected "onlymanyowners" transactions
    // as well as the selection of addresses capable of confirming them (msg.sender is not added to the owners!).
    function multiowned(address[] _owners, uint _required)
        public
        validNumOwners(_owners.length)
        multiOwnedValidRequirement(_required, _owners.length)
    {
        assert(c_maxOwners <= 255);

        m_numOwners = _owners.length;
        m_multiOwnedRequired = _required;

        for (uint i = 0; i < _owners.length; ++i)
        {
            address owner = _owners[i];
            // invalid and duplicate addresses are not allowed
            require(0 != owner && !isOwner(owner) /* not isOwner yet! */);

            uint currentOwnerIndex = checkOwnerIndex(i + 1 /* first slot is unused */);
            m_owners[currentOwnerIndex] = owner;
            m_ownerIndex[owner] = currentOwnerIndex;
        }

        assertOwnersAreConsistent();
    }

    /// @notice replaces an owner `_from` with another `_to`.
    /// @param _from address of owner to replace
    /// @param _to address of new owner
    // All pending operations will be canceled!
    function changeOwner(address _from, address _to)
        external
        ownerExists(_from)
        ownerDoesNotExist(_to)
        onlymanyowners(keccak256(msg.data))
    {
        assertOwnersAreConsistent();

        clearPending();
        uint ownerIndex = checkOwnerIndex(m_ownerIndex[_from]);
        m_owners[ownerIndex] = _to;
        m_ownerIndex[_from] = 0;
        m_ownerIndex[_to] = ownerIndex;

        assertOwnersAreConsistent();
        OwnerChanged(_from, _to);
    }

    /// @notice adds an owner
    /// @param _owner address of new owner
    // All pending operations will be canceled!
    function addOwner(address _owner)
        external
        ownerDoesNotExist(_owner)
        validNumOwners(m_numOwners + 1)
        onlymanyowners(keccak256(msg.data))
    {
        assertOwnersAreConsistent();

        clearPending();
        m_numOwners++;
        m_owners[m_numOwners] = _owner;
        m_ownerIndex[_owner] = checkOwnerIndex(m_numOwners);

        assertOwnersAreConsistent();
        OwnerAdded(_owner);
    }

    /// @notice removes an owner
    /// @param _owner address of owner to remove
    // All pending operations will be canceled!
    function removeOwner(address _owner)
        external
        ownerExists(_owner)
        validNumOwners(m_numOwners - 1)
        multiOwnedValidRequirement(m_multiOwnedRequired, m_numOwners - 1)
        onlymanyowners(keccak256(msg.data))
    {
        assertOwnersAreConsistent();

        clearPending();
        uint ownerIndex = checkOwnerIndex(m_ownerIndex[_owner]);
        m_owners[ownerIndex] = 0;
        m_ownerIndex[_owner] = 0;
        //make sure m_numOwners is equal to the number of owners and always points to the last owner
        reorganizeOwners();

        assertOwnersAreConsistent();
        OwnerRemoved(_owner);
    }

    /// @notice changes the required number of owner signatures
    /// @param _newRequired new number of signatures required
    // All pending operations will be canceled!
    function changeRequirement(uint _newRequired)
        external
        multiOwnedValidRequirement(_newRequired, m_numOwners)
        onlymanyowners(keccak256(msg.data))
    {
        m_multiOwnedRequired = _newRequired;
        clearPending();
        RequirementChanged(_newRequired);
    }

    /// @notice Gets an owner by 0-indexed position
    /// @param ownerIndex 0-indexed owner position
    function getOwner(uint ownerIndex) public constant returns (address) {
        return m_owners[ownerIndex + 1];
    }

    /// @notice Gets owners
    /// @return memory array of owners
    function getOwners() public constant returns (address[]) {
        address[] memory result = new address[](m_numOwners);
        for (uint i = 0; i < m_numOwners; i++)
            result[i] = getOwner(i);

        return result;
    }

    /// @notice checks if provided address is an owner address
    /// @param _addr address to check
    /// @return true if it's an owner
    function isOwner(address _addr) public constant returns (bool) {
        return m_ownerIndex[_addr] > 0;
    }

    /// @notice Tests ownership of the current caller.
    /// @return true if it's an owner
    // It's advisable to call it by new owner to make sure that the same erroneous address is not copy-pasted to
    // addOwner/changeOwner and to isOwner.
    function amIOwner() external constant onlyowner returns (bool) {
        return true;
    }

    /// @notice Revokes a prior confirmation of the given operation
    /// @param _operation operation value, typically keccak256(msg.data)
    function revoke(bytes32 _operation)
        external
        multiOwnedOperationIsActive(_operation)
        onlyowner
    {
        uint ownerIndexBit = makeOwnerBitmapBit(msg.sender);
        var pending = m_multiOwnedPending[_operation];
        require(pending.ownersDone & ownerIndexBit > 0);

        assertOperationIsConsistent(_operation);

        pending.yetNeeded++;
        pending.ownersDone -= ownerIndexBit;

        assertOperationIsConsistent(_operation);
        Revoke(msg.sender, _operation);
    }

    /// @notice Checks if owner confirmed given operation
    /// @param _operation operation value, typically keccak256(msg.data)
    /// @param _owner an owner address
    function hasConfirmed(bytes32 _operation, address _owner)
        external
        constant
        multiOwnedOperationIsActive(_operation)
        ownerExists(_owner)
        returns (bool)
    {
        return !(m_multiOwnedPending[_operation].ownersDone & makeOwnerBitmapBit(_owner) == 0);
    }

    // INTERNAL METHODS

    function confirmAndCheck(bytes32 _operation)
        private
        onlyowner
        returns (bool)
    {
        if (512 == m_multiOwnedPendingIndex.length)
            // In case m_multiOwnedPendingIndex grows too much we have to shrink it: otherwise at some point
            // we won't be able to do it because of block gas limit.
            // Yes, pending confirmations will be lost. Dont see any security or stability implications.
            // TODO use more graceful approach like compact or removal of clearPending completely
            clearPending();

        var pending = m_multiOwnedPending[_operation];

        // if we're not yet working on this operation, switch over and reset the confirmation status.
        if (! isOperationActive(_operation)) {
            // reset count of confirmations needed.
            pending.yetNeeded = m_multiOwnedRequired;
            // reset which owners have confirmed (none) - set our bitmap to 0.
            pending.ownersDone = 0;
            pending.index = m_multiOwnedPendingIndex.length++;
            m_multiOwnedPendingIndex[pending.index] = _operation;
            assertOperationIsConsistent(_operation);
        }

        // determine the bit to set for this owner.
        uint ownerIndexBit = makeOwnerBitmapBit(msg.sender);
        // make sure we (the message sender) haven't confirmed this operation previously.
        if (pending.ownersDone & ownerIndexBit == 0) {
            // ok - check if count is enough to go ahead.
            assert(pending.yetNeeded > 0);
            if (pending.yetNeeded == 1) {
                // enough confirmations: reset and run interior.
                delete m_multiOwnedPendingIndex[m_multiOwnedPending[_operation].index];
                delete m_multiOwnedPending[_operation];
                FinalConfirmation(msg.sender, _operation);
                return true;
            }
            else
            {
                // not enough: record that this owner in particular confirmed.
                pending.yetNeeded--;
                pending.ownersDone |= ownerIndexBit;
                assertOperationIsConsistent(_operation);
                Confirmation(msg.sender, _operation);
            }
        }
    }

    // Reclaims free slots between valid owners in m_owners.
    // TODO given that its called after each removal, it could be simplified.
    function reorganizeOwners() private {
        uint free = 1;
        while (free < m_numOwners)
        {
            // iterating to the first free slot from the beginning
            while (free < m_numOwners && m_owners[free] != 0) free++;

            // iterating to the first occupied slot from the end
            while (m_numOwners > 1 && m_owners[m_numOwners] == 0) m_numOwners--;

            // swap, if possible, so free slot is located at the end after the swap
            if (free < m_numOwners && m_owners[m_numOwners] != 0 && m_owners[free] == 0)
            {
                // owners between swapped slots should't be renumbered - that saves a lot of gas
                m_owners[free] = m_owners[m_numOwners];
                m_ownerIndex[m_owners[free]] = free;
                m_owners[m_numOwners] = 0;
            }
        }
    }

    function clearPending() private onlyowner {
        uint length = m_multiOwnedPendingIndex.length;
        // TODO block gas limit
        for (uint i = 0; i < length; ++i) {
            if (m_multiOwnedPendingIndex[i] != 0)
                delete m_multiOwnedPending[m_multiOwnedPendingIndex[i]];
        }
        delete m_multiOwnedPendingIndex;
    }

    function checkOwnerIndex(uint ownerIndex) private pure returns (uint) {
        assert(0 != ownerIndex && ownerIndex <= c_maxOwners);
        return ownerIndex;
    }

    function makeOwnerBitmapBit(address owner) private constant returns (uint) {
        uint ownerIndex = checkOwnerIndex(m_ownerIndex[owner]);
        return 2 ** ownerIndex;
    }

    function isOperationActive(bytes32 _operation) private constant returns (bool) {
        return 0 != m_multiOwnedPending[_operation].yetNeeded;
    }


    function assertOwnersAreConsistent() private constant {
        assert(m_numOwners > 0);
        assert(m_numOwners <= c_maxOwners);
        assert(m_owners[0] == 0);
        assert(0 != m_multiOwnedRequired && m_multiOwnedRequired <= m_numOwners);
    }

    function assertOperationIsConsistent(bytes32 _operation) private constant {
        var pending = m_multiOwnedPending[_operation];
        assert(0 != pending.yetNeeded);
        assert(m_multiOwnedPendingIndex[pending.index] == _operation);
        assert(pending.yetNeeded <= m_multiOwnedRequired);
    }


   	// FIELDS

    uint constant c_maxOwners = 250;

    // the number of owners that must confirm the same operation before it is run.
    uint public m_multiOwnedRequired;


    // pointer used to find a free slot in m_owners
    uint public m_numOwners;

    // list of owners (addresses),
    // slot 0 is unused so there are no owner which index is 0.
    // TODO could we save space at the end of the array for the common case of <10 owners? and should we?
    address[256] internal m_owners;

    // index on the list of owners to allow reverse lookup: owner address => index in m_owners
    mapping(address => uint) internal m_ownerIndex;


    // the ongoing operations.
    mapping(bytes32 => MultiOwnedOperationPendingState) internal m_multiOwnedPending;
    bytes32[] internal m_multiOwnedPendingIndex;
}

// File: mixbytes-solidity/contracts/security/ArgumentsChecker.sol

// Copyright (C) 2017  MixBytes, LLC

// Licensed under the Apache License, Version 2.0 (the "License").
// You may not use this file except in compliance with the License.

// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND (express or implied).

pragma solidity ^0.4.15;


/// @title utility methods and modifiers of arguments validation
contract ArgumentsChecker {

    /// @dev check which prevents short address attack
    modifier payloadSizeIs(uint size) {
       require(msg.data.length == size + 4 /* function selector */);
       _;
    }

    /// @dev check that address is valid
    modifier validAddress(address addr) {
        require(addr != address(0));
        _;
    }
}

// File: contracts/BoomstarterToken.sol

/**
 * @title Boomstarter project token.
 *
 * Standard ERC20 burnable token plus logic to support token freezing for crowdsales.
 */
contract BoomstarterToken is ArgumentsChecker, multiowned, BurnableToken, StandardToken, TokenWithApproveAndCallMethod {

    // MODIFIERS

    /// @dev makes transfer possible if tokens are unfrozen OR if the caller is a sale account
    modifier saleOrUnfrozen(address account) {
        require( (m_frozen == false) || isSale(account) );
        _;
    }

    modifier onlySale(address account) {
        require(isSale(account));
        _;
    }

    modifier privilegedAllowed {
        require(m_allowPrivileged);
        _;
    }


    // PUBLIC FUNCTIONS

    /**
     * @notice Constructs token.
     *
     * @param _initialOwners initial multi-signatures, see comment below
     * @param _signaturesRequired quorum of multi-signatures
     *
     * Initial owners have power over the token contract only during bootstrap phase (early investments and token
     * sales). To be precise, the owners can set sales (which can transfer frozen tokens) during
     * bootstrap phase. After final token sale any control over the token removed by issuing disablePrivileged call.
     * For lifecycle example please see test/BootstarterTokenTest.js, 'test full lifecycle'.
     */
    function BoomstarterToken(address[] _initialOwners, uint _signaturesRequired)
        public
        multiowned(_initialOwners, _signaturesRequired)
    {
        totalSupply = MAX_SUPPLY;
        balances[msg.sender] = totalSupply;
        // mark initial owner as a sale to enable frozen transfer for them
        // as well as the option to set next sale without multi-signature
        m_sales[msg.sender] = true;
        Transfer(address(0), msg.sender, totalSupply);
    }

    /**
     * @notice Standard transfer() but with check of frozen status
     *
     * @param _to the address to transfer to
     * @param _value the amount to be transferred
     *
     * @return true iff operation was successfully completed
     */
    function transfer(address _to, uint256 _value)
        public
        saleOrUnfrozen(msg.sender)
        returns (bool)
    {
        return super.transfer(_to, _value);
    }

    /**
     * @notice Standard transferFrom but incorporating frozen tokens logic
     *
     * @param _from address the address which you want to send tokens from
     * @param _to address the address which you want to transfer to
     * @param _value uint256 the amount of tokens to be transferred
     *
     * @return true iff operation was successfully completed
     */
    function transferFrom(address _from, address _to, uint256 _value)
        public
        saleOrUnfrozen(msg.sender)
        returns (bool)
    {
        return super.transferFrom(_from, _to, _value);
    }

    /**
     * Function to burn msg.sender's tokens. Overridden to prohibit burning frozen tokens
     *
     * @param _amount amount of tokens to burn
     *
     * @return boolean that indicates if the operation was successful
     */
    function burn(uint256 _amount)
        public
        saleOrUnfrozen(msg.sender)
        returns (bool)
    {
        return super.burn(_amount);
    }

    // ADMINISTRATIVE FUNCTIONS

    /**
     * @notice Sets sale status of an account.
     *
     * @param account account address
     * @param isSale enables this account to transfer tokens in frozen state
     *
     * Function is used only during token sale phase, before disablePrivileged() is called.
     */
    function setSale(address account, bool isSale)
        external
        validAddress(account)
        privilegedAllowed
        onlymanyowners(keccak256(msg.data))
    {
        m_sales[account] = isSale;
    }

    /**
     * @notice Same as setSale, but must be called from the current active sale and
     *         doesn't need multisigning (it's done in the finishSale call anyway)
     */
    function switchToNextSale(address _nextSale)
        external
        validAddress(_nextSale)
        onlySale(msg.sender)
    {
        m_sales[msg.sender] = false;
        m_sales[_nextSale] = true;
    }

    /// @notice Make transfer of tokens available to everyone
    function thaw()
        external
        privilegedAllowed
        onlymanyowners(keccak256(msg.data))
    {
        m_frozen = false;
    }

    /// @notice Disables further use of privileged functions: setSale, thaw
    function disablePrivileged()
        external
        privilegedAllowed
        onlymanyowners(keccak256(msg.data))
    {
        // shouldn't be frozen otherwise will be impossible to unfreeze
        require( false == m_frozen );
        m_allowPrivileged = false;
    }


    // INTERNAL FUNCTIONS

    function isSale(address account) private view returns (bool) {
        return m_sales[account];
    }


    // FIELDS

    /// @notice set of sale accounts which can freeze tokens
    mapping (address => bool) public m_sales;

    /// @notice allows privileged functions (token sale phase)
    bool public m_allowPrivileged = true;

    /// @notice when true - all tokens are frozen and only sales can move their tokens
    ///         when false - all tokens are unfrozen and can be moved by their owners
    bool public m_frozen = true;

    // CONSTANTS

    string public constant name = "BoomstarterCoin";
    string public constant symbol = "BC";
    uint8 public constant decimals = 18;

    uint public constant MAX_SUPPLY = uint(36) * uint(1000000) * uint(10) ** uint(decimals);
}