Monster Bash: Fix sprite hotspot and make padding pixels transparent
Zone 66: Add support for map tilesets
Zone 66: Handle special 320x200 images stored in tilesets
Zone 66: Fix tileset transparency (was inverted)
Zone 66: RLE decoding change, fonts now work

Turns out some tiles have pixels stored beyond the tile's dimensions and these
should be discarded rather than wrapped onto the next line.