Fixed sky atmosphere flickering on Mac/Intel
Added backgroundColor to Scene
Updated CHANGES.md
Merge branch 'master' into background
Merge branch 'master' into background
Updated CHANGES.md
Merge branch 'master' into background
Merge branch 'master' into background
Removed incorrect Mac/Intel fix
Merge master to background
Merge branch 'master' into background

Conflicts:
	CHANGES.md
Merge pull request #420 from AnalyticalGraphicsInc/background

Fixed sky atmosphere flickering on Mac
Added MeshFilters.encodeAttribute
Fixed polygon jitter
Added doc and tests for encode
Removed TODO comment
Added Matrix2.fromRotation
Added rotation to matrices
Added textureMatrix to Polygon
Remove textureMatrix from Polygon. Add textureRotationAngle to setPositions and configureFromPolygonHierarchy of Polygon.