Request:  MySQL support

I'm starting to like PermissionsEx less and less, but I can't seem to find a viable alternative.  As far as I can tell, they're the only ones who have SQL support, specifically MySQL, and we NEED that for our server.  I think it's the only thing that would keep me from switching over, so if you guys were to add that into this plugin, I would jump to it in a heartbeat.
