when we destroy a markers layer, remove all of its tiles. do not, however, destroy them... because they were not created here.

git-svn-id: http://svn.openlayers.org/trunk/openlayers@541 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Layer/Markers.js

@@ -20,6 +20,16 @@ OpenLayers.Layer.Markers.prototype =
         this.markers = new Array();
     },
     
+    /**
+     * 
+     */
+    destroy: function() {
+        this.clearMarkers();
+        markers = null;
+        OpenLayers.Layer.prototype.destroy.apply(this, arguments);
+    },
+
+    
     /** 
     * @param {OpenLayers.Bounds} bounds
     * @param {Boolean} zoomChanged
@@ -52,6 +62,17 @@ OpenLayers.Layer.Markers.prototype =
         }
     },
 
+    /**
+     * 
+     */
+    clearMarkers: function() {
+        if (this.markers != null) {
+            while(this.markers.length > 0) {
+                this.removeMarker(this.markers[0]);
+            }
+        }
+    },
+
     /** clear all the marker div's from the layer and then redraw all of them.
     *    Use the map to recalculate new placement of markers.
     */