Doomlike Dungeons

Fixed a bug where spawner culling wasn't working properly; target number of spawners was uneffected by diffifulty and had was calculated in the thousands so that no spawner was ever culled.  (This mostly effects small and tiny dungeons.  Huge dungeons should not be effected at all.)

Added config option to turn culling off.

Spawner calling tries to make medium and smaller dungeons have a spawner densidty like that of large dungeon;  the smaller room size otherwise increases spawner density because of the smaller room size.  This has been an (intended) feature for a long time, was apparently broken.