Implemented a Basic TLS

Proposed solution as a simple, secure, and modular transport layer.

Uses peer keys for signing only (which they probably should be restricted to), and a shared key is derived through ECDH.  Provides forward secrecy, data secrecy, data integrity, and mutual authentication.  Borrows the idea of cipher suites/negotiation from TLS for modularity.

Protocol:
Step 1:  Hello = (Random, MultiPublicKey, Supported Algorithms)
Step 2:  Exchange = (EECDH Public Key, Sig(Hello1 || Hello2 || EECDH Public Key))
Step 3:  Finish = E("Finish")

Atm, it hasn't been integrated with the rest of the code base yet.

Peer review/suggestions welcome, as always.
can this function thats being returned have a named type to denote its purpose?