Open Sesame!

Eureka! Managed to get some doors in that open and close, so v. happy about that.
Still need to do north-south facing doors. I can't do a simple _rotation = xxx on them which is a bit of a bugger as all the verticals rotate as well. We'll see if I can get that fixed by tomorrow. I think tomorrow is just going to be clean up day without any more development. A pity as I was on a roll, and was thinking about doing locked doors that you could only open with a key...that just would be too exciting!