title: NSFilePresenter -presentedSubitemDidAppearAtURL: method never gets called
body: <p>I have an object which conforms to NSFilePresenter protocol that represents my document-based application document package. When a new file is created inside the package, either programmatically using NSFileManager with proper NSFileCoordination methods or via Finder i only got <code>-presentedSubitemDidChangeAtURL:</code> event, but not seeming so obvious in this case <code>-presentedSubitemDidAppearAtURL:</code>.</p>
  
  <p>Is this an expected behavior or i am doing something wrong?</p>
  
  <p>The comments on <code>-presentedSubitemDidAppearAtURL:</code> in NSFilePresenter state it clear:</p>
  
  <blockquote>
    <p>Be notified that a file or directory contained by the directory has been added. If this method is not implemented but <code>-presentedItemDidChange</code> is, and the directory is actually a file package, then the file coordination machinery will invoke <code>-presentedItemDidChange</code> instead.</p>
  </blockquote>