Bug fixes + Burn the Corpses

One of the complaints I got was the massive piling up of corpses, and if there's anything that can be done about them. I think an "incinerator"  room would be a great way to handle that. But since there's so many way to implement such room, I decided to forgo that for now, and use a simpler solution. 

Since you can use a lighter to burn mobs and inflict damage on them, you should be able to burn corpses as well. So, I've added a tutorial hint as well, showing that you can remove corpses by burning those bodies.