THINGS TO DO

(These should be resolved before releasing the next version.)

Disable disallowed painting layers.

Fix tcl/tk material, elevation painting.

Don't allow linear types to be background when painting.

Fix drawing of cylinder areas.

Fix modes when switching from design back to game.

Fix where moving units while designing leaves leftover images of
units on own side.

In Windows version, handle error displays prior to tcl/tk interface
setup without needing console.

Fix behavior of protection table.
