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