These tests attempt to remove a non-child node from an entity reference and 
expect a NO_MODIFICATION_ALLOWED_ERR.  A NOT_FOUND_ERR would be equally 
appropriate.  It is unclear whether the test meant to remove a non-child node.

The patch performs the same modification but will accept either code then if 
the entity was resolved (not required if not validating) attempts a removal of 
a child node and expects only NO_MODIFICATION_ALLOWED_ERR.