Modify recent --with-layout option to set these variables first from

the config.layout file (or specified file) and allow the any other
configuration arguments to override portions of that layout.
ie. --prefix etc.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@82455 13f79535-47bb-0310-9956-ffa450edef68