title: NSMenuItem is not enabled swift
body: <p>I have a NSMenuItem in my project: </p>
  
  <pre><code>var statusBar = NSStatusBar.systemStatusBar()
  var statusItem : NSStatusItem = NSStatusItem()
  var menuItem : NSMenuItem = NSMenuItem()
  var mainMenu = NSMenu()
  
  override func viewDidLoad() {
      super.viewDidLoad()
  
      menuItem.title = "Holidays"
      menuItem.action = Selector("setWindowVisible:")
      menuItem.target = nil
      menuItem.keyEquivalent = "M"
      menuItem.enabled = true
      mainMenu.addItem(menuItem)
  
      statusItem = statusBar.statusItemWithLength(-1)
      statusItem.menu = mainMenu
      statusItem.title = statusItem.menu?.itemAtIndex(0)?.title
  
  }
  </code></pre>
  
  <p>It adds the item to menu, but it isn't enabled: </p>
  
  <p><a href="http://i68.fastpic.ru/big/2015/0116/39/8e444aa8fb6f113bcdad2753e915b439.jpeg" rel="noreferrer">http://i68.fastpic.ru/big/2015/0116/39/8e444aa8fb6f113bcdad2753e915b439.jpeg</a></p>
  
  <p>And the selector is valid too, the function <code>setWindowVisible</code> exists in the same class: </p>
  
  <pre><code>func setWindowVisible(sender : AnyObject?) {
      self.window!.orderFront(self)
  }
  </code></pre>