Fix crash when morphing from 2D to 3D.
Updates based on review.
Merge pull request #889 from AnalyticalGraphicsInc/issue884

Fix Issue 884
Added Extent.fromDegrees
Fixes #864
Merge pull request #891 from hpinkos/cloneUndefined

Fixes #864
Minor doc fixes
Merge master to batching
Added DebugAppearance
Renamed Appearance to MaterialAppearance
Added streamlined base Appearance
Merge branch 'batching' into extrudePolygon