* Add CacheMinExpire directive to set the minimum time in seconds to cache a document

  in the case that no valid expire time was supplied with the document.

Submitted by: Brian Akins <brian.akins turner.com>
Reviewed by: Ruediger Pluem


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@369811 13f79535-47bb-0310-9956-ffa450edef68