There is no longer a _default_ path layout for APACI configure.

This means the user _HAS_ to specifiy a path layout _explicitly_.

Added a generic --with-layout=[FILE:]ID option. ID here is a layout
identifier, currently "Apache" and "GNU" are pre-defined in the file
config.layout.  Custom layouts are possible by using FILE:ID as the
argument where the layout ID is taken from FILE.

The config.layout file consists of <Layout ID>..</Layout> sections
where inside those sections "path_variable: path_value" pairs can be
specified. These lines are converted to path_variable='path_value'.

These are primarily Ralf's changes that I am commiting to allow me to
begin working on another phase of these configure changes.

Reviewed by:	Randy Terbush, Ken Coar, Jim Jagielski


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@82427 13f79535-47bb-0310-9956-ffa450edef68