Enhanced the httpd -h option's output to make it readable by

normal users and to improve internal documentation of override mask.
Reviewed by: Ben Laurie <ben@gonzo.ben.algroup.co.uk>


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@76848 13f79535-47bb-0310-9956-ffa450edef68