Initial commit to add support for 32 bit index buffers in Terrain Tiles.
Adjusted ambient lighting to brighten scenes that use terrain vertext lighting.
Merge branch 'terrainIndices32bit' of https://github.com/abwood/cesium into terrainIndices32bit
Cleanup.
Added unit tests for testing Quantized-Mesh tiles with 32bit indices.  Minor cleanup.
Merge remote-tracking branch 'agi/master' into terrainIndices32bit
Updated Changes.MD.  Merged in agi/master
Added IndexDatatype.createTypedArrayFromArrayBuffer.  Using this new method and the original IndexDatatype.createTypedArray throughout.
Cleanup.
Updated unit tests to use waitsForPromise where appropriate.
Unit tests for IndexDatatype.createTypedArrayFromArrayBuffer
Unit test polish.
Merge remote-tracking branch 'agi/master' into terrainIndices32bit
Merge pull request #2189 from abwood/terrainIndices32bit

Add support for Quantized-Mesh terrain tiles with more than 64k vertices