Add a @SmartNotifyChange annotation that triggering the notification once the value of the property is changed

Unlike the @NotifyChange annotation, the @SmartNotifyChange annotation will check the value of each property that declared in it.
The value of both properties ('*' and '.') in @SmartNotifyChange will be treated as @NotifyChange, i.e. it won't check anything.
If developer wants to gain some performance enhancement on this, they can use the API instead - http://books.zkoss.org/wiki/ZK_Developer's_Reference/MVVM/ViewModel/Notification#Notify_Programmatically