got initial encrypted communication working

Ignore-this: 150bcdb337097f3a24f3dc4975c22e3f

At first I am simply using public key encryption to send messages back and forth... I am breaking up
the messages into chunks which are encrypted individually... but right now the chunks are of a fixed
max size which could be bad.

I am preparing for using DH to establish a shared secret so that I can use AES for actuall communication...

darcs-hash:20130821064803-c21fe-86ff79cee3f5635a6e18201cbaa05f1bb7fbc8e1