Finish Security Hardening

We need to ensure that communication between the agent and streamserver is encrypted as it transfers over the wire, and preferably also using public/private keys if possible. We should also see if we can do something to ensure that each agent can cryptographically verify that the message they receive is from the right server (pub/priv key encryption here again) so we don't have a situation where a bad actor spoofs commands to a minion out in the world.