Permalink gets a destroy method. Fixes #594.

git-svn-id: http://svn.openlayers.org/trunk/openlayers@2935 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/Permalink.js

@@ -32,6 +32,20 @@ OpenLayers.Control.Permalink.prototype =
         }
     },
 
+    /**
+     * 
+     */
+    destroy: function()  {
+        if (this.element.parentNode == this.div) {
+            this.div.removeChild(this.element);
+        }
+        this.element = null;
+
+        this.map.events.unregister('moveend', this, this.updateLink);
+
+        OpenLayers.Control.prototype.destroy.apply(this, arguments); 
+    },
+
     /** Set the map property for the control. 
      * 
      * @param {OpenLayers.Map} map