Do not overlap frustums when rendering translucent geometry.
Update CHANGES.md.
Merge branch 'master' into multifrustum

Conflicts:
	CHANGES.md
Fix the rim lighting in GridMaterial to accept backface normals.
Start of aircraft model
Merge pull request #1504 from AnalyticalGraphicsInc/grid-material-backface

Fix the rim lighting in GridMaterial to accept backface normals.
Merge branch 'master' into multifrustum
Minor doc fix.
Merge pull request #1507 from AnalyticalGraphicsInc/minorDocFix

Minor doc fix
Merge pull request #1459 from AnalyticalGraphicsInc/multifrustum

Fix translucent multifrustum artifact
Reorder CHANGES.md
Updated CHANGES.md
Merge master to gltf
Merge branch 'gltf' into gltfDefaults