Calculate billboard width and height after loading image into texture atlas.
tweak test
Merge pull request #2254 from AnalyticalGraphicsInc/billboardDimensions

Calculate billboard width and height after loading image into texture atlas
Fix whitespace
Add GPlates screenshot to README.md
Update Geometry constructor test.
Merge pull request #2242 from AnalyticalGraphicsInc/wrapLongitude

PolylineGeometry IDL split
Merge branch 'master' into xzPlaneSplit

Conflicts:
	Source/Core/GeometryPipeline.js