when we destroy a feature, remove its popup from the map through the removePopup() function

git-svn-id: http://svn.openlayers.org/trunk/openlayers@526 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Feature.js

@@ -44,6 +44,12 @@ OpenLayers.Feature.prototype= {
      * 
      */
     destroy: function() {
+
+        //remove the popup from the map
+        if (this.popup != null) {
+            this.layer.map.removePopup(this.popup);
+        }
+
         this.events = null;
         this.layer = null;
         this.id = null;