Improved extruded polygon performance and slightly improve combining geometries. Also reduce memory allocations.
More extruded polygon optimizations.
Revert GeometryPipeline changes and slightly reduce memory allocations.
Merge branch 'master' into geometry-perf
Reduce garbage collection in WallGeometryLibrary.
Minor performance improvement by removing inverse trig calls in a loop and remove more temporary object creation.
Remove missing cartesian allocation that could be a scratch.
Add Entity support for box geometry

Still needs cleanup and tests.
Specs for BoxGraphics and BoxGeometryUpdater.
Merge branch 'master' into geometry-perf
Updates from review.
Merge pull request #2329 from AnalyticalGraphicsInc/geometry-perf

Improve extruded polygon and wall performance.
Compute size of color array for polyline geometry instead of concating many arrays.
Minor temporary object creation in SimplePolylineGeometry. Mostly code clean up.
Compute the exact number of points on the ellipse boundary where it could have been an overestimate.
Compute the number of ellipse outline positions up front and index into array.
Clean up dynamic geometry updaters

The dynamic geometry updaters in the DataSource layer did not have
the same semantics as the rest of the visualizations system.  Mainly,
an undefined value would cause Cesium to crash instead of simply not
rendering an object.  This change uses the newer Property.get helper
functions in order to both clean up the code and follow the same rules.

Fixes #2252
Clean up ellipse index computation.
Use removeAndDestroy in ModelVisualizer.
Merge branch 'geometry-updater-cleanup' into entity-box