Remove 2.5d floorspaces

This is going to be a very controversial change, so I only did it to three levels. My reasoning for removing the floorspaces is as follows:

1. With floorspaces removed, we can finally ditch the interact button and just use UP
2. Movement on floorspaces feels different than the rest of the game.
3. The floorspace code is complicated (and large). Editing floorspace levels is also complicated, because you have to move the bottoms of items around.
4. Removing floorspaces means all levels play exactly the same. No change of controls. Doors are always up.

This is what the three levels look like. They function almost exactly the same.

![untitled 2](https://f.cloud.github.com/assets/34893/558732/79b18a2e-c42d-11e2-9590-e1bd7f966501.png)
![untitled](https://f.cloud.github.com/assets/34893/558734/7ba165a2-c42d-11e2-9162-c222679cd9f5.png)
![untitled 3](https://f.cloud.github.com/assets/34893/558730/4323c666-c42d-11e2-89a3-b03079835409.png)

Also, removing floorspaces breaks some things. Pots no longer work.