mod_cache: Ignore response headers specified by no-cache=header and

private=header as specified by RFC2616 14.9.1 What is Cacheable. Ensure
that these headers are still processed when multiple Cache-Control 
headers are present in the response. PR 54706


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1478382 13f79535-47bb-0310-9956-ffa450edef68