Fix some inconsistency in the paths printed in the update summary.
Fix some inconsistency in the paths printed in the update summary.

* subversion/svn/update-cmd.c
  (print_update_summary): Calculate a relative path to display, if
    possible, and convert to local style.  This should make the paths
    used in the summary section match those used in the "Updating ..."
    header lines.

Reported by: julianfoad

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion