Fix picking in 2D with rotated map.
Add tests for picking in 2D.
Update CHANGES.md.
Merge branch 'pickCoordinates2D' into picking

Conflicts:
	Source/Scene/Scene.js
	Specs/Scene/PickSpec.js
Merge branch 'pickCoordinates2D' into picking
Merge branch 'pickCoordinates2D' into picking
Merge pull request #1361 from AnalyticalGraphicsInc/picking

Picking in 2D