Merge pull request #323 from bitcoinjs/netcompat

HDNode: add optional network flag for importing
transaction/builder: s/txin/txIn/g
1.4.0
index: expose Block
1.4.1
crypto: add deprecation warnings
ecdsa/HDNode: use node crypto for Hmacs
1.4.2
tests/integration: add HDNode private key recovery example
tests/integration: move crypto-like tests to test/integration/crypto.js
README: update README links
package: use cb-helloblock for integration tests
tests/integration: add k-value derivation and private key recovery example
Merge pull request #327 from bitcoinjs/cryptoint

Add advanced cryptographic integration tests
tests: remove unused variables
tests: remove unused variable
tests: remove extraneous anonymous function
TxBuilder: extract ExtractSignatures to free function
TxBuilder: re-order to avoid mutation in case of failure
TxBuilder: sign now signs inputs in known publicKey order