Optimize transform handling.
Invalidate before changing rendering related properties.
Fix rotation setter.
Fix and optimize transform helpers.
Optimize transform invalidation.
Don't apply an identity transform.
Reuse pointer objects.
Use this as target coordinate space in _getContentBounds.
Return earlier from _getTransformedRect in some cases.
Merge pull request #983 from tobeytailor/display

Optimize and cleanup DisplayObject