Added sandstone, stone bricks, desert stone bricks, and sandstone bricks...

What do you think?
If you like them, either give me the thumbs up to merge them, or do it yourself!
EDIT:
Also added: clay, ice, desert cobble, obsidian, gravel, and bookshelf.
![screenshot_1286890644](https://cloud.githubusercontent.com/assets/4390945/3129595/612d748a-e7e6-11e3-955b-b69d10bc4c95.png)

Wow, a lot of commits. Sorry about that!