- add code to
  PushDownRefactoringProcessor.getReferencingElementsFromSameClass()
  to check if references found to the member moved are actually
  referring to the current class and not indirectly via
  sub-classes which will have the member moved to them
- add new tests to PushDownTests

Change-Id: I03edd02a97ed0654b3d19716fcfdad27a8443e89