title: get favicon.co from WKWebView
body: <p>I am using the new wkWebView for OS X and iOS. For a presentation of the webview as an icon, I need the favicon of the presented URL. In the old webview, I could use the function:</p>
  
  <pre><code>var mainFrameIcon: NSImage! { get }
  </code></pre>
  
  <p>How can I get the image by using wkWebView in Swift or Objective-C?</p>