title: Cocoa NSDocument: getting autosave to work
body: <p>Documentation simply states that setting <code>setAutosavingDelay</code> to anything > 0 on the shared doc controller should do it, but after calling </p>
  
  <pre><code>[[NSDocumentController sharedDocumentController] setAutosavingDelay:2.0];
  </code></pre>
  
  <p>in my controller, autosave doesn't seem to work: I neither see anything in <code>~/Library/Autosave Information/</code>, nor is</p>
  
  <pre><code>[[[NSDocumentController sharedDocumentController] currentDocument] autosavedContentsFileURL]
  </code></pre>
  
  <p>initialized. </p>
  
  <p>Note that in my app, normal loading and saving work fine (keyedarchivers, nscoding-based class for my docs, etc).</p>