analysis/highlight tools
bughouse/crazyhouse
-- Make the drawing/highlighting code just touch single squares, rather
- than redrawing the whole board each time (fast though this is,
- touching single squares is all that's necessary, and it would be
- even faster)
-
- Fix highlighting in chess-plain when chess-plain-spacing is set.
chess-coord needs to be applied to a larger area, and also the way
highlight locations are found needs to be recalculated.