Tweak and extend issue #3807 tests.
Tweak and extend issue #3807 tests.

* subversion/tests/cmdline/update_tests.py
  (update_nonexistent_child_of_copy):
    Verify that the 'update' didn't undo the deletion.
  (revive_children_of_copy):
    New XFailing test.
  (test_list): Run it.

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