Modding:
- Add "Unavailable" unique (counterpart to Only Available)
- Unified resource generation checks to include all uniques always
- 'not shown on world screen' unique accepts civ conditionals
- Added adjacency conditionals
- CityCombatant.matchesFilter contains multifilter and civ filter

By tuvus:
- Air unit automation improvement
- Espionage automation

By SeventhM:
- Fix errors when starting games as Maya