Automated city governor

The city governor determines what citizens in a given city shall do. With the city governor, the game engine automatically optimize the city's food, production and trade income: all citizens try to work on available tiles and optimize the income that specified as preference (blue buttons). In new cities the city governor is disabled (three gray buttons on the details sidebar) and it is available only with subscription in case of popupation of the city more than 5, due the greater server load.