Instead of LibGUI and WindowServer building their own copies of the drawing
and graphics code, let's it in a separate LibDraw library.
This avoids building the code twice, and will encourage better separation
of concerns. :^)
This needs more work and polish, but it's a step in a more pleasant and
useful direction.
Also turn QuickShow into a fully-fledged "application". (By that, I really
just mean giving it its own Applications/ subdirectory.)
