Add two XFAIL tests for delete/revert.
Add two XFAIL tests for delete/revert.

* subversion/tests/cmdline/copy_tests.py
  (copy_delete_undo): New helper.
  (copy_delete_delete, copy_delete_revert): New tests.
  (test_list): Mark new tests XFAIL.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion