Room creation returns

I had the room creation switched off for a while, because I was re-inventing the wheel in how the rooms should be placed.

The first thing I noticed was this. It's what we professionals call "island creation". Two systems are created separately and don't connect to each other. In this case caverns and dwarf-made rooms. Well, I guess this could be quite easy to fix, maybe check out if connection was made and if not, use a connecting corridor from one of the rooms or corridor tiles. I think a corridor will usually cross a cavern area, but things like this will happen sometimes.

By the way, I still have to figure out how to prevent corridors meeting a room at sharp corners, creating impossible situation for entrance/door creation. Yes, I know, this is something that I have worked on for a while...