add demo tag
Fix normal upsampling.  Cannot not linearly interpolate oct encoded normals in all cases, due to how the octrahedron is unwrapped.
Cleanup.
Added unit test.
Cleanup.
Merge branch 'quantizedMeshUpsampleNormalsFix' of https://github.com/abwood/cesium into quantizedMeshUpsampleNormalsFix

Conflicts:
	Source/Workers/upsampleQuantizedTerrainMesh.js