By tuvus:
- AI units swap-retreat
- Melee units are now more likely to attack cities
- Nukes AI tweaks
- AI values traded gold using inflation

By SomeTroglodyte:
- Tighten Ruleset validation for Terrain
- Automated units stay automated after upgrade
- Fix Mod checker crash on RekMod
- Account for badly-defined Android font
- City overview refreshes for changes done in city

💚 add tests for city population manager - By Framonti

Fix [stats] unique adding multiple times - By SeventhM