Fix lots of code. Made a mistake with npm and the former version was left
totally untested. This one has actually been tested and used.
Make sure voxelAt* methods return the old value for the voxel, not the one
that was just set. I believe this was a bug, as voxel-engine seems to expect
getting the old block back when calling this function.
Bump patch level as only fixing bugs.
Merge pull request #11 from nakedible/upstream-fixes

Quick fix voxelAtPosition bug