Add render properties and update to voxel-engine 0.20.0

Adds a new 'render' folder, for changing mesher algorithm and type:

![screen shot 2013-12-28 at 10 05 33 pm](https://f.cloud.github.com/assets/5897956/1819005/4abe5980-704f-11e3-83d5-03da9831938e.png)

example:

![screen shot 2013-12-28 at 9 53 40 pm](https://f.cloud.github.com/assets/5897956/1818999/ef5107c4-704d-11e3-813f-b1e6089d9f46.png)
![screen shot 2013-12-28 at 9 53 30 pm](https://f.cloud.github.com/assets/5897956/1819000/ef5259b2-704d-11e3-8ea9-a5034332f6ba.png)

Uses new feature available in voxel-engine 0.20.0 with https://github.com/maxogden/voxel-engine/pull/93 (fwiw I also have a few other options added in https://github.com/deathcap/voxel-debug but they require further changes to other projects)