Enabled CityCanAcquirePlot with fix
Added City and Player Yield percentage modifiers

-Exposed SetLeaderYieldBoost to lua
-Exposed GetLeaderYieldBoost to lua
-Exposed SetCityResidentYieldBoost to lua
-Exposed GetCityResidentYieldBoost to lua
-Modified EA_DEBUG some more
Merge pull request #7 from ls612/Ea

Added City and Player Yield percentage modifiers