title: Change color to a title of a button in Swift
body: <p>I have problems changing the color of the title of a NSButton. I tried this:</p>
  
  <pre><code>button.setTitleColor(NSColor.blackColor())
  </code></pre>
  
  <p>or this</p>
  
  <pre><code>button.titleColor = NSColor.blackColor()
  </code></pre>
  
  <p>and this </p>
  
  <pre><code>button.title.textColor = NSColor.blackColor()
  </code></pre>
  
  <p>but none of these three methods seems to be available! How could that be possible, the compiler says that these method are not present. </p>
  
  <p>AppKit and Cocoa are imported. What is the solution?</p>