librocket GUI support

Nice, I’ll check it out, as soon as possible.

RDB, does your example from above work on your system with threading-model Cull/Draw
support-threads t?
I get random crashes if I fiddle with the buttons etc. I guess it’s because of librocket lack of threading support(http://librocket.com/wiki/PlannedFeatures), but just to make sure I didn’t break something. :slight_smile: