-Feature: make penalty for road stop occupancy user configurable
-Fix [FS#1944]: road vehicles would not pick an empty drive through stop. Now they will *if* the penalty for driving around is less than the occupancy penalty
-Fix [FS#1495]: long (articulated) road vehicles could block loading of others when the following road vehicle already got 'permission' to go to the next bay even when it could not reach it
-Change: improve the throughput of the drive through road stops by letting them stop closer together
-Fix: use a flag instead of TL_NO_ROADS to forbid towns to build roads. The flag is ignored during world generation, so there won't be 'ghost' towns anymore
-Feature: town layout is now stored per town, so it is possible to (manually) set different layout for each town