Delete (weird) Block.__cmp__

How does one order water, lava and dirt?
I believe __cmp__ to be for total order; does not make sense for Vec3

(0,1) vs (1,0) - partial ordering ftw
Merge branch 'master' into feature/delete-odd-orderings

Conflicts:
	minecraft/vec3.py
Merge branch 'master' into feature/delete-odd-orderings

Conflicts:
	minecraft/block.py
Merge pull request #29 from py3minepi/feature/delete-odd-orderings

Delete strange ordering