OK... a good commit point (we don't quite compile yet though...)

Pull out the worker scoreboard cruft and start moving most
worker stuff to shm. Use slotmem for workers and provide
space for growth.

Redo logic:

  ap_proxy_define_*
  ap_proxy_create_*
  ap_proxy_initialize_*

Right now just for workers, but lay framework for balancers
as well. The idea is to break out the functional parts
to make it easy for dynamics. Defining is simply describing
the worker, and tucking that info away. When we create, we
go ahead and create the shared memory, etc... Initialize
is simply to allow child process to access the shm...

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1058622 13f79535-47bb-0310-9956-ffa450edef68