New Windows-only XFail test for issue #2556: map a virtual drive to a working copy and do some basic commit & update actions.
New Windows-only XFail test for issue #2556: map a virtual drive
to a working copy and do some basic commit & update actions.

* subversion/tests/cmdline/update_tests.py
  (update_wc_on_windows_drive): New test for issue 2556.
  (test_list): add the new test to the list.

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