KML using the layertree

When you configure a layer as having KML capabilities, I think there is a little bug or maybe did I misunderstand something.

When you click on the KML icon in the layertree, following happens:
* The Google Earth plugin is activated -> OK
* The KML is loaded in the plugin -> OK
* The KML file is loaded in the OL map -> not good at all...

I don't think that the KML should be loaded into the OL map, because:
* The layer can already be turned on in the layertree
* The KML file might be quite big, thus OL has problems to load it as it is interpreted as a vector layer.

You can test that on http://sitn.ne.ch/sitn_dev/wsgi/theme/environnement, turn layer `Protection des eaux` on and click on the Google Earth link button in the layertree. 

If FF complains because a script is going wild, just tell it to continue... Imagine what happens if using IE ;-)

Did I miss something ?? or is that really some kind of issue??