Tile swapping with transported units in the tile, checks *who* is transporting the units

City states don't get continually researchable techs automatically

Modding:
- Resolved automation crash for units with "gain free [building]" uniques
- Allow multipying cached uniques

By touhidurrr:
- more detailed multiplayer authentication

By SomeTroglodyte:
- CityScreen's top-right widget better sized for mobile
- Better save/load in map editor