Misc. updates

- Removed source files which were pretty useless.
- Added back working texture definitions. Need to work out how to make
them different from Hexen's without breaking PWADs.
- Resized the textures to correct dimensions.
- Converted some graphics to the right palette. Need to work out how to
convert them to the right format.
- This revision is broken in at least Chocolate Hexen. Need to work on
fix.