Update the perchild MPM. At this point, it is possible to specify that

a child process runs as a specified user.  That child process is not
currently tied to a virtual host.  Using this MPM, I can launch Apache
and have it serve as both nobody and rbb.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@85916 13f79535-47bb-0310-9956-ffa450edef68