Resurrect a bit of code to test mod_dav_svn's creation of locks with
an expiry date.

* subversion/tests/cmdline/lock_tests.py
  (create_dav_lock_timeout): New.
  (test_list): Add new test.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1579610 13f79535-47bb-0310-9956-ffa450edef68