Added support for binding to multiple observable objects (properties).

data/observable/observable.d.ts

@@ -99,6 +99,11 @@ declare module "data/observable" {
          */
         notify(data: EventData): void;
 
+        /**
+         * Notifies all the registered listeners for the property change event.
+         */
+        notifyPropertyChange(propertyName: string, newValue: any): void;
+
         /**
          * Checks whether a listener is registered for the specified event name.
          * @param eventName The name of the event to check for.