Remove duplicate positions from polylines.
Do not modify the polyline positions passed in by the user.
Only return a new array is duplicates were found.
PolylinePipeline.removeDuplicates clean up.
Merge pull request #2196 from AnalyticalGraphicsInc/polylineDuplicates

Remove duplicate positions from polylines.
Update CHANGES.md.
Add GeometryPipeline.compressNormals.
Add GeometryPipeline.compressNormals tests.
Compress Primitive normals, tangents, and binormals. Pack when possible.
Fix DebugAppearance specs.
Add functions to store 2 byte oct encoded normals in a single float.
Merge branch 'octEncoding' into compressNormals
Use oct encoded Primitive normals and texture coordinates stored in a single float.
Fix modified shader when compressing texture coordinates.
Merge pull request #2205 from AnalyticalGraphicsInc/octEncoding

Oct Encoding
Merge branch 'master' into compressNormals
If normal, tangent, and binormal are present, then compess to two floats. Removed texture coordinate compression.
Add FeatureDetection.isFirefox and firefoxVersion.
Revert back to storing a single normal as two floats. Fix the rest of the tests.
Clean up code modifying vertex shader.