title: Button inside custom Callout View not responding (Swift)
body: <p>I have a custom MKPinAnnotationView created as so:</p>
  
  <pre><code>func mapView(mapView: MKMapView!, viewForAnnotation annotation: MKAnnotation!) -&gt; MKAnnotationView! {
      if annotation is MKUserLocation {
          //return nil so map view draws "blue dot" for standard user location
          return nil
      }
  
      let reuseId = "pin"
      var pinView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId) as? MKPinAnnotationView
  
      if pinView == nil {
          pinView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: reuseId)
          pinView!.canShowCallout = false
          pinView!.animatesDrop = true
          pinView!.pinColor = .Red
          pinView!.draggable = true;
      } else {
          pinView!.annotation = annotation
      }
  
      return pinView
  }
  </code></pre>
  
  <p>Then I add a subview to it later with a button like this:</p>
  
  <pre><code>func mapView(mapView: MKMapView!, didSelectAnnotationView view: MKAnnotationView!) {
      view.addSubview(confirm)
  }
  </code></pre>
  
  <p>The problem is that the button inside the subview is not responsive at all. What could be causing that? I already tried playing around with userInteraction enabled.
  Thanks</p>