Merge pull request #1 from bitpay/master

Sync with Bitpay
Merge pull request #2 from bitpay/master

Sync with Bitpay
Added return value check

The openssl_random_pseudo_bytes function will return false on failure.
Create Fingerprint.php

To be used as the passphrase for the transparent read/write encryption.
Create FingerprintTest.php
Fix for issue using the class in a CLI environment
Fix for failing unit test
Merge pull request #40 from ionux/master

Added fingerprint class for filesystem read/write encryption use