librocket GUI support

Alright thank you ! I managed to write it in C++ and it works wonders !

But there’s a problem I know how to solve with PGButtons but not with the libRockets !

If you want to ignore the clicks intercepted by a PGButton, you would do this :

button->get_region()->set_suppress_flags(MouseWatcherRegion::SF_mouse_button);

But I can’t find a way to do this with RocketRegions. Is there something to do that ?