Add ProxyBlock directive w/IP address caching. Add IP address caching to

NoCache directive as well. ProxyBlock works with all handlers; NoCache now
also works with FTP for anonymous logins. Still more code cleanup.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@77387 13f79535-47bb-0310-9956-ffa450edef68