Pull out duplicated code to proxy_util...

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1453875 13f79535-47bb-0310-9956-ffa450edef68
rename extension module... tunnel is more accurate

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1453876 13f79535-47bb-0310-9956-ffa450edef68