Typo in tooltip config of GoogleEarth plugin

By the way I see that this plugin uses "menuText" as many other CGXP plugins.
Why don't we also use "buttonText" that would be interesting to add a default button text instead of explicitly adding
```
actionConfig: {
    text: "foobar"
}
``` 
as in GMF demo:
https://github.com/camptocamp/demo_geomapfish/blob/master/demo/templates/viewer.js#L326
?