Add a stats command to circe

[jgkamat]

This PR adds a stats command to circe. In order to avoid combinining the multiple args (eg: /stats p adams.freenode.net), I split the incoming argument string. Let me know if you think there's a cleaner way to do this, I'm not sure what exactly the convention is here.

I could also use irc-send-raw, but that seems more hacky to me.

Also see the stats command for sytax.

I'm adding this because in the topic of #freenode, it says:

*** Topic for #freenode: Welcome to #freenode | Feel free to message
    staff at any time. You can find us using /stats p (shows
    immediately-available staff) or /who freenode/staff/* (shows all
    staff) |

which dosen't work in circe, as there is no stats command.

Let me know if anything seems off.

[jgkamat]

(just in case @jorgenschaefer didn't see the new commit, bump :P)

I'm fine with waiting though, because this isn't too important, and I'm not in a rush :)

[jorgenschaefer]

Thank you!