Removes a few non-behavioral workarounds for older versions.
Refs #5502, #2891.
Accepted By: asterix
Comments by: vladislavbelov
Differential Revision: https://code.wildfiregames.com/D2076
This was SVN commit r22508.
ScEd: Compilation fixes.
Atlas: Screen-space to world-space conversion when editing terrain.
Wireframe option. Minor wxWidgets 2.6.1 fixes. AoE3Ed.
This was SVN commit r2698.