On '1.8.x-r1589360' branch: Use qsort() directly since svn_sort__array() is 
not available in 1.8.x.

* subversion/libsvn_diff/util.c
  (propchange_sort): Update docstring.
  (svn_diff__display_prop_diffs): Use qsort() instead of svn_sort__array().


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.8.x-r1589360@1624267 13f79535-47bb-0310-9956-ffa450edef68