*) mod_rewrite: Add support for starting External Rewriting Programs

   as non-root user on UNIX systems by specifying username and group name
   as third argument of RewriteMap directive.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1664565 13f79535-47bb-0310-9956-ffa450edef68