Changed name to a more cool one.
Issue #62 - Stubs for subscribe/unsubrscribe message handling.
Issue #62 - Added implementation of subscribe/unsubscribe message handling. Subscribing needs a little bit of fixing - I've included why in FIXME comment.
Issue #62 - Remove user subscriptions on removing user connections.
Issue #62 - Fixing previous typos. Added sending best orders to subscribers.