added more property methods to PGPKeyring
improved the key loader mechanism (and it actually works now)
added a mechanism for MPIFields to securely delete its contents by memsetting NULL bytes over the top of it using ctypes.memset
set the version for our cryptography requirement to 0.3
added a method to util to compute the modular multiplicative inverse of two numbers (borrowed the code from the cryptography 0.4 codebase; this can go away when cryptography 0.4 actually comes out)
fixed a typo
starting to allow for Packet creation from scratch
initial pass at creating a new PGPSignature object from scratch
miscellaneous cleanups and code improvements
SIGNING!
Test signing!