CMS-3639 Remove dependency of path on region and page component elements
RegionView and PageComponentView now is instantiated with their data objects
RegionView and PageComponentView are no longer dependent of path set element ("data-live-edit-region" and "data-live-edit-component")
Removed no longer needed PageComponentAddedCommand since creation of PageComponent now happens in DragDropSort.
PageViewItemsParsedEvent is no longer needed since views are instantiated with their data objects
Introduced LiveEditPage - the coming main controller class for LiveEdit page code