Change the scheme handler hook to include worker.

We will probably need the balancer too, but that can wait for now.
Other undocumented changes (shame,shame) in proxy_util.c

Submitted by: mturk


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@104600 13f79535-47bb-0310-9956-ffa450edef68