Custom notification CSS class

[Clashsoft]

Currently, the CSS class for generated <div>s is always one of notification_{info,success,warning,error}. It would be nice to allow a custom mapping, e.g. for Bootstrap classes: alert alert-{info,success,warning,danger}. Perhaps with a mapping function:

Extension notificationExtension = NotificationsExtension.create().withClassMapper((Notification n) -> {
  return n == Notification.ERROR ? "alert alert-danger" : "alert alert-" + n.name().toLowerCase();
};

[McFoggy]

Added in new 1.1.0.