Added gpg decryption, adapted from yamlgpg
Changed config key for gpg code
Removed extraneous caching config
Modified error-raising code
Modified gpg exception behavior
Fixed missed old-style variable name
Added case for nil return
Changed failure behavior for consistency
Updated readme
Small change to readme
Changed handling of gpg config options
Added ':gpg' check to initialization
Changed readme
Added exception handling for wrong GPG keys
Fixed exception code to return correct values
Fixed failure on nil bug
Modified to ensure exception on key not found
Fixed exception on key not found
Further work on key-not-found exceptions
Small change to exception message