Legend does not clear oActiveLayer when clicked off

[pdeschamps]

It looks as though we are not catching the toggle state of a legend item.

When you click on a layer in the legend and then click it again it should set this.getMap().oActiveLayer to null. It looks as though that it does not have a case for that. in legend.js

        this.selection = new Jx.Selection({
            onSelect: function(item) {
                var treeItem = item.retrieve('jxTreeItem');
                var data = treeItem.options.data
                if (data instanceof Fusion.Layers.Group) {
                    this.getMap().setActiveLayer(null);
                } else {
                    this.getMap().setActiveLayer(data);
                }
            }.bind(this)
        });