Setting the bounds of any NxWidget causes it to lose all state

For example

```
(
c = NxComment(Rect(50, 50, 50, 50));
c.text = "hello";
)

c.bounds = Rect(50, 50, 50, 50)
```

I realise bounds_ is undocumented, but moving a widget is a pretty common thing to do, and this is pretty surprising. Looking at the nxserver OSC messages it looks like bounds just recreates the widget. 

