On the 1.6.x-issue3646 branch: Merge r948512 from trunk.

* src-branch-1.6.x-4
  Mergeinfo update.

* subversion/tests/cmdline/merge_tests.py
  (cyclic_record_only_merge_creates_self_referential_mergeinfo): No
   conflicts, but needed to adjust this new test to work on 1.6, i.e.
   svntest.actions.run_and_verify_merge doesn't accept expected mergeinfo
   and elision output.



git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.6.x-issue3646@957332 13f79535-47bb-0310-9956-ffa450edef68