Conditional worker uniques no longer cause crashes when disabled

Improvement hotkeys can no longer trigger twice when 2 improvements have the same key

Specific civ images override style images

Resolved A* "units with no movement consider occupied tiles moveable to" bug

City borders and city buttons no longer disappear near the south edge

CPU improvements 

By unciv-loof:
- Add mirroring type to map editor
- Reorder map types