jabber: Register "hipchat" protocol (only minimal support for now)
Another take on the subprotocols idea that, IMO, was a failure.
Unlike the other implementation, this one doesn't touch gtalk/facebook
accounts, it just adds another copy of the "jabber" prpl called "hipchat".
And, based on the protocol name:
- sets JFLAG_HIPCHAT to jabber_data
- sets the default value of the "server" setting
- only includes the oauth setting for jabber-type accounts
This is slightly more "hardcoded" but honestly facebook and gtalk are
just as hardcoded as this.
Copying the prpl is needed because the meaning of the usernames is
completely different (there's no srv lookup stuff either)
