City centers don't provide resources you don't have tech to extract

AI: Settlers no longer stuck in endless loops

modding: Fixed certain unit uniques with tile conditionals

AI clears inquisitors from city centers to make way for spaceship units

Add the SellBuilding Unique  - By PLynx01

Add 'gain stat by game speed' and 'improvement speed with filter' uniques  - By SeventhM

Add a TriggerUponDiscoveringTile unique  - By karmaBonfire

Support for Leader voices - By SomeTroglodyte