title: Xamarin.Forms.Switch sends Toggled event when value is updated
body: <p>So I'm still debuting with <code>Xamarin.Forms</code>. So far so good, if I put aside a few pesky bugs I encountered. Here's the new guy. Maybe one of you could tell me if I'm doing something wrong.</p>
  
  <p>Basically, I have a <code>Xamarin.Forms.Switch</code> on my interface, and I'm listening for changes in its state with the <code>Toggled</code> event. The doc says about this event: "Event that is raised when this Switch is toggled <strong>by the user</strong>."</p>
  
  <p>Unfortunately, when I update the value of the switch programmatically, the event fires.</p>
  
  <pre><code>var mySwitch = new Switch ();
  mySwitch.Toggled += (object sender, ToggledEventArgs e) =&gt; {
      Console.WriteLine ("Switch.Toggled event sent");
  };
  mySwitch.IsToggled = true;
  </code></pre>
  
  <p>Any way to prevent the event from firing / to know that it's not the user who triggered it?</p>