Add OnSelected event on RadioElements

[henrikweimenhog]

Add to the RadioElement class

    public Action<object, EventArgs> OnSelected {
        get;
        set;
    }

and in the Selected method in the RadioElement class add the following

    if (OnSelected != null)
            OnSelected (this, EventArgs.Empty);

[timrisi]

RadioElement inherits the Tapped Action from the base StringElement class, and is called as part of base.Selected (dvc, tableView, indexPath) in the RadioElement's Selected method.

[migueldeicaza]

Tim confirms it works now.