Added simple chunk <-> world link
Added direct getX && getZ
Merge remote-tracking branch 'origin/master'

Conflicts:
	src/com/ingotpowered/api/world/Chunk.java
Add type, dimension, and difficulty definitions to world
Added some chunk / world implementation
Merge remote-tracking branch 'upstream/master'
Added some safety/ error reporting
Merge pull request #4 from Ichbinjoe/master

Added chunk/world relationship code, simple state fuctions