Add missing documentation.
Add specs and fix problem uncovered by them.
Merge branch 'master' into dynamicScene-buffering

Conflicts:
	Source/DynamicScene/DataSourceDisplay.js
Merge remote-tracking branch 'origin/master' into dynamicScene-buffering
Changes after review.
Merge remote-tracking branch 'origin/master' into dynamicScene-buffering

Conflicts:
	Source/DynamicScene/StaticGeometryPerMaterialBatch.js
Improve DataSource geometry instance attribute performance

Geometry instance attributes are much more expensive to set than I realized when I implemented DataSource geometry batching.  This modifies the batching code to cache the last attribute value and only set it if it's changed.  This improves performance by doing less work, but also greatly reducing the amount of garbage generated in scenarios with lots of geometry that changes color or visibility over time.
Fix bounding sphere computation for polygons.
Add test.
Merge branch 'master' into polygon-bounding-sphere
Fix label documentation and example.
Fix tests.
Fix polygon outline bounding sphere computation.
Merge pull request #1625 from AnalyticalGraphicsInc/polygon-bounding-sphere

Polygon bounding sphere
Merge remote-tracking branch 'origin/master' into label-docs
Changes per review.
Merge pull request #1626 from AnalyticalGraphicsInc/label-docs

Fix label documentation and example.
Merge pull request #1624 from AnalyticalGraphicsInc/dirty-work

Improve DataSource geometry instance attribute performance
Fix typo.
Merge pull request #1617 from AnalyticalGraphicsInc/dynamicScene-buffering

Enable asynchronous geometry processing in DynamicScene