* Implement unit tests for key expression fidelity to user input for hardened paths
* Create HardenedType, rework BIP32Node to take Option[HardenedType] as a parameter
* Fix docs
* Added crypto project and decoupled BitcoinSLogger from NetworkElement
Decoupled BitcoinSLogger from Factory
Moved NetworkElement into crypto project
Moved Factory and BitcoinSUtil (renamed to BytesUtil) to crypto project
Moved MaskedToString to crypto project
Added BytesUtil to imports and cleaned up CryptoUtil.recoverPoint
Moved the rest of crypto stuff to the crypto project
Moved crypto tests to crypto-test project
* Added documentation for crypto project
