add ogrinfo test

Author: jmckenna

en/ogc/wfs_server.txt

@@ -436,6 +436,12 @@ Which should return something like:
     gml_id: String (0.0) NOT NULL
     NA2DESC: String (0.0)
     NA3DESC: String (0.0)
+    
+.. TIP::
+   If you notice "Geometry: Unknown (any)" in the ogrinfo response, you
+   should set the "gml_geometries" and "gml_geom_type" properties in 
+   the LAYER.METADATA of your WFS server mapfile, as in the example 
+   mapfile above.
 
 Support for GET and POST Requests
 *********************************