ra_serf: Fix up mergeinfo implementation.
ra_serf: Fix up mergeinfo implementation.

* subversion/libsvn_ra_serf/mergeinfo.c
  (mergeinfo_context_t): Change curr_path to a stringbuf from char *.
  (start_element): Clear the stringbuf when we open the element.
  (end_element): Check the correct lengths; properly copy the data to the
  result hash.
  (cdata_handler): This function can be called multiple times, so we must
  append each time.
  (minfo_request_head, minfo_request_tail): Move from const char []'s to...
  (MINFO_REQ_HEAD, MINFO_REQ_TAIL): make a #define as not all compilers agree
  on char[] semantics.
  (svn_ra_serf__get_mergeinfo): Set curr_path to "", use #define's.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@865615 13f79535-47bb-0310-9956-ffa450edef68

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