art asset and extensibility update (see discrip)

updated the inventory and slots (personal preference..), added
inventory.xcf overlay for easy changing as a template by the Gimp, and
made TERRAINMAP_BLOCK_SIZE for easy adjusting for larger terrain.png
files
add 157139a from boskee, see addit'l info please...

For some reason windows wont let me do path.join() for folders, so i
have to keep all assets in the main folder.  Any suggestions would be
appreciated.
res folder, modified from boskee

organized now, had ta friend help me to troubleshoot whey a function
worked in linux, and not in windows.  ended up had to re-index the
resources folder.  if we hack this a bit more, as boskee suggested, we
may be able to do skins and texture packs.
Fix sound resource paths

- Set pyglet resource path and reindex the files so that it can
  find and load sound files.
Temporary solution to sound problems.
Merge commit '5b221b72ba7dfb0a847282d7a8b454041b30424f'
Fixed save system (saving whole World object caused to save for example batch object).
Revert "Fixed save system (saving whole World object caused to save for example batch object)."

This reverts commit 47937399bfc4e8e4adf04458353db4040d9ef0ff.
Use pyglet resource.path to index sound resource files
Thanks to PR #32 by @tfaris
Pyglet does not like backslashes at all, and wants to be fed /'s only
Show cracks while breaking blocks
Bugfix
Merge remote-tracking branch 'avelanarius/master'
Merge commit '1161ef80ccb31d9c894fe592c7cdeb5c91716c50'

Conflicts:
	sounds.py
Fixed save system.
Added leaves break sound.
Generate stone blocks beneath the surface.
Added ore generation on random depth.
Added ore generation on random depth (2).
glass_block and lamp_block

renamed old glass_block to lamp_block, new glass_block.  need to set
item background color to transparent
Merge commit 'f133b07b6becd045ded2c5881e9db026b87dcd0f'

Conflicts:
	blocks.py
	main.py
	resources/textures/inventory.png
	resources/textures/texture.png
	resources/textures/texture.xcf