add block.js and tests
bufferutils: add varIntBuffer
block: adds getUTCDate function
block: re-order functions to project standard
Merge pull request #300 from bitcoinjs/block

Block.js
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
remove deprecated functionality
Transaction/TxBuilder: move all param coercion to TxBuilder
Transaction/RawTx: renames TxBuilder to Transaction
RawTransaction: re-order functions to project standard
RawTransaction: rename tmpTx to tx
add ECPair module
remove ECKey, ECPubKey, replace with ECPair
doc: no section headers
tests: avoid extraneous anonymous function
travis: ignore Node 0.11 until sinon fixes implemented