Follow-up to r24903, tweak merge tests to specifically exercise that code.
Follow-up to r24903, tweak merge tests to specifically exercise that code.

* subversion/tests/cmdline/merge_tests.py
  (merge_to_path_with_switched_children): Perform a merge to a target which
  has immediate children that are switched and have otherwise elidable
  mergeinfo.  Also improve comments a bit.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@864996 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion