be able to add someone to one's roster by right-clicking in the message window
when someone who's not on your roster messages you and you want to request authorisation to be put on the other person's roster, you can't do it in the very window s/he opened up to you.
currently, you've got to switch to the roster and right-click on the nick (not in roster group), it would be time-saving to be able to right-click in the message window.