Refactor ScreenSpaceEventHandler and the tests substantially.
Hook up pointer events.
fix specs for pointer events
Merge remote-tracking branch 'origin/master' into pointerEvents
Update CHANGES
Merge remote-tracking branch 'origin/master' into pointerEvents

Conflicts:
	CHANGES.md
Split polylines that cross the IDL into lines in the western hemisphere and eastern hemisphere. Modify the primitive and geometry pipelines to handle split geometry.
Merge branch 'master' into xzPlaneSplit

Conflicts:
	Source/Core/GeometryPipeline.js
Keep track of multiple bounding spheres. One for each geometry returned from the pipeline.
Split simple lines using the plane containing the IDL as the splitting plane.
Split triangles using the plane containing the IDL as the splitting plane.
Clean up instance update after splitting geometry.
Clean up copying geometry attribute properties before splitting.
Compute Columbus View/2D bounding sphere from vertex positions projected to 2D.
Merge branch 'master' into xzPlaneSplit
Merge remote-tracking branch 'origin/master' into pointerEvents

Conflicts:
	CHANGES.md
Clean up and centralize loading logic for data sources.
Merge branch 'master' into xzPlaneSplit

Conflicts:
	Source/Scene/Primitive.js
Merge remote-tracking branch 'origin/master' into pointerEvents

Conflicts:
	CHANGES.md
Fix splitting triangles where a vertex position is exactly on the IDL.