* First approach to improve accessiblity
* Clear accessibleElements in addSubview: and willRemoveSubview:
* Adjust comments and rename viewNode to node
* Create new accessible elements if screen coordinates of view changes
* Remove legacy clearing of accessibleElements
* Performance improvements
* Use bounds for screenFrame calculation and indexOfObjectIdentical: in indexOfAccessiblityElement:
* Add ASDK_ACCESSIBILITY_DISABLE compiler flag to disable custom accessibility code in ASDK
* No need to set a frame if a subnode view is an accessibility element and not layer backed