Add more tests.
Add appearance rendering tests.
Add Primitive and createTangentSpaceDebugPrimitive tests.
Add render tests for Primitive in 2D and Columbus view.
Add rendering tests for box, circle, and ellipse geometry. Fix ellipse bounding sphere when at a height above the ellipsoid.
Add ellipsoid, extent, and polygon rendering tests. Fix polygon bounding sphere at a height above the ellipsoid.
Add wall geometry rendering test.
Add simple polyline geometry rendering tests.
Add custom primitive rendering tests.
Revert changes to CesiumViewe.
Updates based on review.
More updates based on review.
More updates after review.
More updates based on review.
Merge branch 'master' into batching

Conflicts:
	Apps/Sandcastle/gallery/Custom Rendering.html
Update Sandcastle example.
Remove conflicting options from PolygonGeometry. Make PolygonGeometry constructor take a polygon hierarchy and add a new fromPositions function.
Merge remote-tracking branch 'origin/batching' into gltf