Doing some graphics!

Today, after fixing annoying bugs (there's still one left, but for now, it's not too much of an issue), I decided to lay off programming for a bit, and started changing a load of background graphics so they're more subtle and don't look like they're in the foreground. There's still quite a bit to do, however. To emphasise that they're backgrounds, I'm going to have to add something to the level editor...