support BIP32 absolute path in BIP32::build_key
BIP39
added notes about ext-intl
added generating entropy for BIP39
added bip39 example and the strong argument of openssl_random_pseudo_bytes
added test for signing P2SH
fixed a mistake made in 4ef7ddc5e867ad8ca6562851088c374884e5d427 that inverted the length check.
this resulted it RawTransactions sometimes thinking it's own signatures were not valid.

fixes #28.
updated exception message and added test for exception
BIP39 classes PSR2 codestyle
fixed PHP5.3 incompatabilites
changed BitcoinLib::validate_address to also validate p2sh addresses.
BIP32 optimization
if this isn't the last derivation then the fingerprint is irrelevant so we can just spoof it!
that way we don't need the public key for the fingerprint
added more tests for BIP32::CKD
Merge pull request #32 from blocktrail/canonical-signature

Canonical signature bad ->cmp check
Merge pull request #29 from blocktrail/bip39

BIP39 implementation
Merge pull request #35 from blocktrail/bip32-ckd-optimization

Bip32 ckd optimization
Merge pull request #34 from blocktrail/validate-address

changed BitcoinLib::validate_address to also validate p2sh addresses.