General fixes to upsampling.
Cleanup and added unit test.
Removed some precision loss that was incurred during upsampling.
Added edgeIndices tests to unit test.
Merge remote-tracking branch 'agi/master' into quantizedMeshUpsampleFixes

Conflicts:
	Source/Workers/upsampleQuantizedTerrainMesh.js
Updated Changes.MD
Minor tweak to add clarity to edgeIndex binning.
Fixed use of local rectangle variables in upsample worker. Cleanup.
Merge pull request #2318 from abwood/quantizedMeshUpsampleFixes

Quantized mesh upsample fixes