more color configurability
(this is related to tickets #357 and #272)
It'd be nice to be able to set the font color to distinguish between contacts who are away, offline, etc. in the roster. Mainly, I'd like to grey contacts out who are away.
It would also be really nice to be able to manually choose every color that's ever used in code -- like the window and button backgrounds in dialogs.py and the cell backgrounds in roster_window.py.