Adding preliminary code for encryption using botan library

Ignore-this: bcebafff7c368e14eb74b0187832bf4d

darcs-hash:20130715222146-c21fe-0b0e7d32c5e9f980e1730349359386bf57e9bdd5
firestr now requires password

Ignore-this: 8d4296a1d95dbbe4053cb2f90caf15bd

Users now have private and public keys!

The private/public keys are created when you first launch firestr and create a user name
and password.

The password is used to encrypt and decrypt the user's private key.

Also now contact info has public key information and invite files store the public key.

This is the first step in putting encryption in place for com

darcs-hash:20130719045110-c21fe-6c21beb873210f403e6a775133eb866dc2d4896a