While "set" is a tad strong (there's just the one component for now), I
had missed the changes when adding ECS systems. Fixes the segfault at
the end of demo1 (ie, when any center text is printed).
Instead of creating new entities for the text views. This approximately
halves the number of entities required to display flowed text, but also
tests the ability to have an entity in multiple hierarchies (the goal of
the ECS component and system changes).
This means that the component id used for hierarchy references must be
passed to Hierarchy_New and Hierarchy_Copy, but does all an entity to
have more than one hierarchy, which is useful for canvases (hierarchies
of views) in the 3d world (the canvas root would have a 3d hierarchy
reference and a 2d (view) hierarchy reference).
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.
