PopupButton is unfinished

```
The PopupButton class seems to be unfinished. There is no event support and the 
popup can not use a custom renderer. Only Strings can be used and the only way 
to receive any kind of event is to register a property listener to the JButton 
component and listen for text change events.


```

Original issue reported on code.google.com by `dlemmermann@gmail.com` on 25 Jan 2011 at 3:10
