title: Replacing UISlider default thumb image with a multilayered image
body: <p>As far as I know there is no such thing as a multilayered image in iOS. If you want to display overlaid images you use UIImageViews.</p>
  
  <p>If UISlider thumb was an image view it would have been easy to do, but since it's an UIImage is there a way to replace it with a multilayered image?</p>