Improve the handling of the ssl-authority-files config option: allow leading and trailing whitespace on the filenames to make it easier for the user to format the list of files.
Improve the handling of the ssl-authority-files config option: allow
leading and trailing whitespace on the filenames to make it easier for
the user to format the list of files.

* subversion/libsvn_ra_serf/util.c:
  (load_authorities): switch to svn_cstring_split() and use its
    builtin param to trim whitespace. then process the resulting array.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1235831 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion