Make some diff tests not depend on ordering of output.
Make some diff tests not depend on ordering of output.

There is no guarentee that all RA layers will return the
information in the same order.

* subversion/tests/cmdline/diff_tests.py
  (diff_git_format_wc_wc,
   diff_git_format_url_wc,
   diff_git_format_url_url): Don't depend on ordering for output.

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