Add the ability to change the floor for an entire room at once
Resolves #38
After much under the bonnet work I’ve decided to put in two long-standing tickets, bulk editing for wall tiles and floor tiles, this commit implements the tile part:
Implementing this got a lot easier by finally introducing the concept of “rooms” a while back. On more good news, doing this will also make implementing the wall counter-part of this ticket a bit easier. However, not happening in release builds, but debug builds is a weird race condition that I will have a look into first. Hopefully that is not going to take too long, but be that as it may, I’m happy to see this happening finally. 🙂