Use mod_rewrite instead of error handlers to redirect to cgimap

Using rewrites is a simpler method then relying on 404 errors and redirecting

Note: For my setup I also have this in the config file to redirect other responses to the api.osm.org servers

```
$HTTP["url"] =~ "/api/.*" {
        proxy.server = ( "" => (        ( "host" => "193.63.75.100"),
                                        ( "host" => "193.63.75.99"),
                                        ( "host" => "193.63.75.103") ) )
}
```