[Xcb] python bindings

[Thomas Hunger]

> Yeah.  It's one of those things that we chucked in there
> because we needed something and couldn't figure out anything
> better offhand.  I'm not super proud of it, and it was
> mostly my idea.  Better docs and a specific tutorial would
> probably help, but it would be cool if we could just replace
> the whole mess with something nicer.

While not happy I now think the current API is just fine. So no more 
strange ideas from my side.

Most people will use a widget set like qt or gtk anyway, so a few 
notes in Vincents tutorial should be enough.

Tom