Solved edge-case missing images bug

Hidden conditionals are hidden in more places

Duplicate notifications are all shown

Fixed infinite air units in cities

Friendship-based modifiers calculated correctly

By SomeTroglodyte:
- UX: Notifications for map units select better when tapped 
- Fix GlobalPoliticsOverviewTable table layout after switching back from diagram 

By SpacedOutChicken:
- Correct Unique parameters doc to display terrain quality