title: CloudKit CKSubscription without notifications?
body: <p>I'm writing a Swift app with CloudKit. When a record is modified in CloudKit by a device, I want the corresponding records to be updated in the local storage of the other devices without displaying a push notification.</p>
  
  <p>Do I need to call <code>registerUserNotificationSettings</code> in <code>didFinishLaunchingWithOptions</code> (meaning that the user has to accept the notifications for my app) even if I don't plan to display any push notification?</p>
  
  <pre><code>application.registerUserNotificationSettings(UIUserNotificationSettings(forTypes: .Alert, categories: nil))
  </code></pre>