title: Cocoa: How to set window title from within view controller in Swift?
body: <p>I've tried to build on a Cocoa app which uses storyboard and Swift in Xcode 6. However, when I tried to alter the title of window from within <code>NSViewController</code>, the following code doesn't work.</p>
  
  <pre><code>self.title = "changed label"
  </code></pre>
  
  <p>When I wrote the above code in <code>viewDidLoad()</code> function, the resultant app's title still remains <code>window</code>.</p>
  
  <p>Also, the following code causes an error, since View Controller doesn't have such property as <code>window</code>.</p>
  
  <pre><code>self.window.title = "changed label"
  </code></pre>
  
  <p>So how can I change the title of window programmatically in Cocoa app which is built on storyboard?</p>