Add the concept and implementation for a runtime config

directory, ala /etc/rc.d/init. Basically, if any of the
config "files" are actually directories, all files in
that directory (and in subdirectories) will be parsed as
config files. Thus you can add new config directives with
no file edits at all, simply file additions.
PR: 6397
Obtained from:
Submitted by:	Lionel Clark <bishop@platypus.bc.ca> (concept + initial patch)
Reviewed by:	William A. Rowe, Jr


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@86377 13f79535-47bb-0310-9956-ffa450edef68