Dialog.showMessage should recognize Component message

[Sciss]

Swing auto-detects JComponentas the message parameter. For example

Dialog.showMessage(message = new javax.swing.JLabel("Hello"))

To use that feature, we currently have to say .peer

Dialog.showMessage(message = new Label("Hello").peer)

It would be good if scala-swing automatically detected a scala.swing.UIElement and unwrap it here.