Introduce proxy_ajp.c : use --enable-proxy-ajp with configuring Apache.

To load it:
+++
LoadModule proxy_ajp_module modules/mod_proxy_ajp.so
+++

And to use it something like:
+++
<Location /examples/>
ProxyPass ajp://backend.example.net:8009/examples/
</Location>
+++

proxy_ajp will not be enabled by default due to ./ajp dependencies

Build magic improvements: mturk, wrowe

Submitted by:  jfclere


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@104556 13f79535-47bb-0310-9956-ffa450edef68