Added an optional function (ap_register_rewrite_mapfunc) which allows

third-party modules to extend mod_rewrite's "int:" internal RewriteMap
functionality.

Concept by:  Tahiry Ramanamampanoharana <nomentsoa@hotmail.com>


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@94939 13f79535-47bb-0310-9956-ffa450edef68