Added command.clj to make adding commands easier. This can be done now with the def-command and def-bot-command functions. Also ported most of the irc interaction functionality from core into irc-connection. Existing bot commands were moved into bot-commands. Lastly, added a <3 command which replies to any message containing a <3 with <3.
Fixed authentication for addpts by adding a higher order function 'authenticated' which takes a nick and a function which executes on auth success and one which executes on auth fail.