ra_serf: Handle authentication challenges when we issue MKACTIVITY request.
ra_serf: Handle authentication challenges when we issue MKACTIVITY request.

* subversion/libsvn_ra_serf/commit.c
  (mkactivity_context_t): Remove unneeded fields folded into handler struct.
  (handle_status_only): Disregard possibly erroneous status message.
  (setup_mkactivity): Remove.
  (open_root): Create handler structure and call svn_ra_serf__request_create();
  don't set the log message in the root dir's property hashes but use a
  separate hash instead for revprops.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@858912 13f79535-47bb-0310-9956-ffa450edef68

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