Added Ronin::Crypto.
Added String#hmac, String#encrypt, String#decrypt (issue #49).
Allow Crypto.cipher to accept options.
Added :hash and :password options to Crypto.cipher.
Default :hash to :sha1.
Changed String#encrypt / String#decrypt to accept options.
Added Crypto.hmac.
Updated String crypto specs.
Added File.hmac, File.encrypt and File.decrypt.
Added Cryptography to the Features section.
Accept :padding in Crypto.cipher.
Moved a common before block up.
Moved ronin/formatting/digest into ronin/crypto.

* Added missing specs for File.md5, File.sha1, File.sha2, File.sha256,
  File.sha512 and File.rmd160.
* Deprecated ronin/formatting/digest.
Added hash identification methods to String (issue #44).
Require 'ronin/crypto' when 'ronin/support' is required.
Revert "Added hash identification methods to String (issue #44)."

This reverts commit b482b678a10c4f997bae47fd92de851a366f7e63.

* There is no way to distinguish between SHA1 and RMD160, or between
  hashes and random hexadecimal Strings.
Merge branch 'crypto' into 0.6.0