Fixed wall-pulling, added safe zone

OK!

So I've fixed the bug where you could pull a piece of junk through a wall and leave it out of reach, and I've also set it so that, when hiding under the bed, you're invulnerable to the vacuum cleaner.

Next up is making volume and other settings persist between runs (should be easy), and then adding some collectible cookies. The game needs more stuff in it, and possibly a smaller initial room. After that, we're on to the good stuff.