When a rewrite to proxy is configured in the server config, a check is made to...

When a rewrite to proxy is configured in the server config, a check is made to make sure mod_proxy is active.  But the same is not done if a rewrite to proxy is configured in an .htaccess file. 

Basically this patch is the block of code from hook_uri2file that does the proxy check, copied to hook_fixup.

Patch provided by Michael Streeter [mstreeter1 gmail.com], slightly modified to use a new APLOGNO

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1838684 13f79535-47bb-0310-9956-ffa450edef68