Make mod_cgid work with SuExec. This has been tested and works reliably

on my machine, but since this is security related, this should be tested
and scrutinized by as many people as possible.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@87905 13f79535-47bb-0310-9956-ffa450edef68