Give MessageDialog actions 'action' properties
Give MessageDialog actions 'action' properties

Otherwise the actions have to be competely overridden to be usable.

Change-Id: Ic4c727b8671630184c37504f8fb9dfbd062547ce

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui