Update to voxel-texture v0.5.0 which uses texture atlases. Bump v0.17.0.

Updates to support voxel-texture v0.5.0 which now loads everything onto a texture atlas and sets UV mappings.

Increases performance roughly by 10 fold. voxel-texture has just about been re-written and is not backwards compatible so I've bumped voxel engine a minor version.

Previously this scene with `chunkDistance: 6` never would run above `7fps` on my macbook but now runs around `30fps` :D
![screen_2013-04-15](https://f.cloud.github.com/assets/99604/383340/1c50bd14-a614-11e2-8a44-2d4510c064fe.png)