add a removeMarker() function

git-svn-id: http://svn.openlayers.org/trunk/openlayers@519 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Layer/Markers.js

@@ -40,6 +40,24 @@ OpenLayers.Layer.Markers.prototype =
         }
     },
 
+    /**
+     * @param {OpenLayers.Marker} marker
+     */
+    removeMarker: function(marker) {
+        var index = null;
+        for(var i=0; i < this.markers.length; i++) {
+            if (this.markers[i] == marker) {
+                index = i;        
+            }
+        }
+        if (index != null) {
+            this.markers.splice(index, 1);
+        }
+        if ((marker.icon != null) && (marker.icon.imageDiv != null) &&
+            (marker.icon.imageDiv.parentNode == this.div) ) {
+            this.div.removeChild(marker.icon.imageDiv);    
+        }
+    },
 
     /** clear all the marker div's from the layer and then redraw all of them.
     *    Use the map to recalculate new placement of markers.