Merge branch 'BuildingMapUpdate' into 'master'

Building map generator update

* The Building map generator can now accommodate rooms.

Rooms are (depending on their design) seamlessly integrated with the BSP-based automatic buildings.
The data.margin_w, data.margin_h parameters are correctly respected, and grids outside of the building area can be specified.

Fixed a bug in RoomsLoader that was incorrectly applying the results of room.prefer_location functions and added some informative print statements when loading room files.



See merge request !348