Cesium VWF Demo

Cesium (http://cesium.agi.com/) is an open source WebGL-based virtual globe and map engine. The changes in this pull request contain a Cesium camera synchronization demo using VWF. 

Camera controls:
*Left drag: Rotate/spin
*Right drag: Zoom in/out
*Mouse Wheel: Zoom in/out
*Shift + Left drag: Horizon view

If the camera views happen to become slightly off from each other (due to inertial movements), hitting the "r" key will re-synchronize the camera across clients.