Fix tabs
Update enableLighting shadow property to detect changes.
Merge pull request #1339 from AnalyticalGraphicsInc/colorcommand

Added scene.debugShowCommands
Merge pull request #1345 from AnalyticalGraphicsInc/enableLighting

Fix CentralBody.enableLighting
Update CHANGES.md.
Remove frustum allocation each frame.
Update doc.
Set shadow properties on cloned frustums to undefined to force matrix updates.
Fix geocoder flights when the camera is following an object.
Set shadow properties to undefined.
Update CHANGES.md.
Merge pull request #1346 from AnalyticalGraphicsInc/frustum

Remove frustum allocation each frame.
Add maximum height to error panel.  Fix #1127
Merge pull request #1348 from AnalyticalGraphicsInc/issue1127

Add maximum height to error panel.  Fix #1127
Merge pull request #1347 from AnalyticalGraphicsInc/geocoderFlights

Geocoder flights
Reset the ScreenSpaceCameraController ellipsoid in the geocoder if the camera was following an object.
Merge pull request #1349 from AnalyticalGraphicsInc/geocoderFlights

Fix Geocoder flights part 2
Merge branch 'master' into gltf
Merge branch 'gltf' into gltf-datastructures2