Add development deps to Gemfile for easy bootstraping
move eventmachine, rake and bacon to Gemfile
Run bacon so rake exits 1 when failing
to_pubkey_script_sig supports compressed pubkeys
ignore log4r warning in require_dependency
Bitcoin::Script: invalid if script larger than 10_000 bytes
add Bitcoin::Script::DISABLED_OPCODES
add Bitcoin#network_project
fix warnings

  lib/bitcoin/script.rb:94: warning: already initialized constant OP_2MUL
  lib/bitcoin/script.rb:95: warning: already initialized constant OP_2DIV
  spec/bitcoin/spec_helper.rb:75: warning: already initialized constant CHECKPOINTS
add generate_tx.rb and simple_network_monitor_and_util.rb examples
add basic ppcoin support
add basic litecoin support
add basic freicoin support
store cumulative block work as bigint
validation: pass block timestamp to signature verification and ignore difficulty on testnet3