Added some new terrain: Walls, floors, signs, and doors. Walls are always impassable, floors always passable (except to aquatic creatures). Shifted over the existing basic cave to use walls and floors instead of mountains and grass.
Added coinage. Beasts may drop 1, 2, or 3 coins. The hero can only carry 3 and will leave the remainder behind.
Fixed a bug in cleave where the hero could hit himself from swinging diagonally. Fixed a bug around using scrolls on a npc.