use new WFS tile

git-svn-id: http://svn.openlayers.org/trunk/openlayers@169 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Layer/WFS.js

@@ -53,7 +53,7 @@ OpenLayers.Layer.WFS.prototype =
     addTile:function(bounds, position) {
         url = this.getFullRequestString(
                      { bbox:bounds.toBBOX() });
-        var tile = new OpenLayers.Tile.Image(bounds, url, this.tileSize);
+        var tile = new OpenLayers.Tile.WFS(bounds, url, this.tileSize);
         tile.draw();
         tile.setPosition(position);
         this.div.appendChild(tile.img);