More blocks by textures

code edits + texture.png. allows for 64 blocks now.
boskee Merge

merged with boskee, will mod later.
(dont know how to do this on Windows, sorry)
more terrain options

options 1-3 now generate 1 block only worlds with the specified block,
new "4" does original terrain generation, change how hillheight works,
still does "overflow" against the wall though.  Merged code with
avelanarius codebase.
Merge commit '031aa91e644485a067b72b56750267fffb9c7801'

Conflicts:
	blocks.py
	entity.py
	inventory.py
	items.py
	main.py