Oculus UI 2.0

This is a pretty major change to the Oculus UI when using the hydra controllers. It also fixes some bugs with the sixense controllers.

Notable changes:
* Hydras now project a laser pointer onto the 3D UI that allows for easier picking of controls.
* 3D UI is now stereoscopic. Bet you didn't notice that it wasn't :P
* Fixed some bugs, including a magnification window selection bug that was quite annoying.
* Allow selection outside of the UI, Up to 180 degrees horizontally and vertically, which is useful for editVoxels.js
* Applied motion damping to the tip position of the hydras, which makes editModels.js more pleasant.
* Made it so that the all the rays that use the controllers point in the correct direction.
* Made the controller ball and disk thingy scale correctly with the avatar.
* Added a helper function to the avatar that allows one to easily scale a world space position relative to the avatar.