Support Cache-Control: no-cache with a header name, and private with a

header name, which causes a cached entry to require revalidation (ie
is always not-fresh), as per RFC2616 14.9.1.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1023399 13f79535-47bb-0310-9956-ffa450edef68