Caverns

It seems like there's two features missing to make good caverns.

1. The ability to designate areas as "underground" so that sunlight skips them. This will also be required for multi-level maps so this may be in the works.
2. The ability to use the AI object placement without walls and floor tiles. If you're making a cave you want natural walls, but you might still want to designate different sections as rooms. Right now you can create a room and then delete the walls, but there are no transparent floor tiles to allow the ground texture to be the floor.