LOD support to Models & Particles, and some other tweaks

* Adds palm rotation to the placeModelsWithHands.js to demonstrate rotation of models

* debug clean up to placeModelsWithHands.js

* handles "LOD" for particles and models - basically uses the built in support in OctreeElement for determining if an Octree element should be visible based on LOD and distance to viewer, and only renders those elements within the LOD boundary

* LOD wired up to LOD Slider in interface AND auto-LOD adjustment.