Adds compatibility_group to building objects.
It is more groundwork for future expansions.
Right now stations tiles with different compatibility_group will not be joined together to one big station.
I am using this to make small, cheap service stations for spacing purposes.
Like this:
Obj=building
Name=RoadServiceStation
type=stop
waytype=road
intro_year=1820
intro_month=7
noconstruction=1
NoInfo=1
Dims=1,1,2
level=1
compatibility_group=1
station_capacity=1
station_price=500
station_maintenance=10
BackImage[0][0][0][0][0][0]=service-road.0.0
FrontImage[0][0][0][0][0][0]=service-road.0.1
BackImage[1][0][0][0][0][0]=service-road.0.2
FrontImage[1][0][0][0][0][0]=service-road.0.3
icon=> service-road.0.5
cursor=service-road.0.4