[1.1] Dev - unchecking "Draw Fog" now only shows ground layer, no resources

[Nycorawr]

Since 1.1, unchecking draw fog removes the fog, however, it then also hides the wall/resource layer only revealing the underlying terrain.

This happens with or without mods, on new and existing save games.

[ison]

Yes, it's an optimization, so we don't even draw fogged things.