Nodes labels on two lines

Hi,

Is it possible to insert a line break within a node label?

I tried to do that directly in the gexf file with `<br>`, `<br />`, or `\n`. But it didn't work.
For example, in the miserables.gexf file:

```
<nodes>
      <node id="0.0" label="Myriel<br>SomeText">
```

Also tried to do that in the js code but without success (I'm new to js).

Any idea?
Thank you.
