create APIMethod for obtaining the view port, this is needed by GeoExt to append the map panel items there so that they don't interfere with the zoombox for example

lib/OpenLayers/Map.js

@@ -612,6 +612,17 @@ OpenLayers.Map = OpenLayers.Class({
             }
         }
     },
+
+    /** 
+     * APIMethod: getViewport
+     * Get the DOMElement representing the view port.
+     *
+     * Returns:
+     * {DOMElement}
+     */
+    getViewport: function() {
+        return this.viewPortDiv;
+    },
     
     /**
      * APIMethod: render