V1.1 - Cave tiles

With the monster pack out (here!) I've finally got around to updating this tileset.

New stuff:

• Cave walls. Same format as the other walls, but also with some extra tiles for transitioning to darkness.
• Some extra dirt floor tiles.
• Lever! (3 states)

As a small thanks to everyone who supported this package early, I decided to make the cave tiles a mini update to the dungeon tileset. I'll be moving onto the overworld tiles next.

Thanks as always!

-P