This causes some problems with linking if libQFgui is linked with
libQFrenderer (which is necessary in the long run), but it seems
everything gets away with it for now (which, tbh, I don't like).
Font and text handling is very much part of user interface and at least
partially independent of rendering, but does fit it better with GUI than
genera UI (ie, both graphics and text mode), thus libQFgui as well as
libQFui are built in the ui directory.
The existing font related builtins have been moved into the ruamoko
client library.