Introduce a per request version of the remote IP address, which can be

optionally modified by a module when the effective IP of the client
is not the same as the real IP of the client (such as a load balancer).


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1204968 13f79535-47bb-0310-9956-ffa450edef68