Stats from followers unique fixed

City-state units work with 'get era' function

Ruleset validation for negative-weight ruin rewards

By SomeTroglodyte:
- Fix crash for trade notifications as Spectator / waiting for player
- Fix Unit rename popup offering up the icon

Solved worker automation crash  - By willjallen

By SeventhM:
- Add "Unable to pillage tiles" unique
- Fix objects being purchable with a blocking conditional

Stats per Stat unique - By PLynx01