Add support for distributed caching of SSL Sessions inside memcached, using apr_memcache, which is present in APR-Util 1.3/trunk.

This was originally written at ApacheCon US 2005 (San Diego), and was sent to the list:
http://mail-archives.apache.org/mod_mbox/httpd-dev/200512.mbox/%3C439C6C07.9030904@force-elite.com%3E

This version is slightly cleaned up, and of course, uses the now bundled apr_memcache, rather than an external dependency.



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@545379 13f79535-47bb-0310-9956-ffa450edef68