remove unused base58 fixtures
Transaction: optional script for addInput
Transaction: simplify fromBuffer verbosity
add block.js and tests
bufferutils: add varIntBuffer
remove base58check

Use bs58check package solely from here on.
rename Message to message
crypto: remove Hmac* exposure in API
crypto: re-work fixtures for simplicity
HDNode: remove toBuffer/toHex
all: remove deprecated functionality
Wallet: fix impl. and tests after deprecated APIs removed
Transaction/TxBuilder: move all param coercion to TxBuilder
remove Wallet
Transaction/RawTx: renames TxBuilder to Transaction
RawTransaction: re-order functions to project standard
RawTransaction: rename tmpTx to tx
tests: remove unnecessary test

This functionality is tested already through the fixtures.
RawTransaction: avoid statement repetition

ECMAScript guarantees order of execution of object literal expressions
in the order they are written.
add ECPair module