Added QuadRenderer to render shaded/colored quads. Added DebugOverlay to World to show A* bidi search cost per cell.
Now coloring A* cells by owning player color. Added checkbox to cheats menu.
Exposed PathSearch.owner and removed Player argument from PathFinder functions.
Lame attempts to improve A*.
DebugOverlay improvements to only render inside viewing range.
apply recent refactoring to quad renderer
Merge pull request #2738 from Mailaender/a-star

A-star debug overlay