title: How to set the background image for a SKScene?
body: <p>Since currently it is not possible to set the color to of a <code>SKScene</code> to <code>clearColor</code>, by doing </p>
  
  <pre><code>-(id)initWithSize:(CGSize)size {
      if (self = [super initWithSize:size]) {
  
  
          self.backgroundColor = [SKColor clearColor];
  
      }
      return self;
  }
  </code></pre>
  
  <p>As seen here: <a href="https://stackoverflow.com/questions/19780215/skcolor-clearcolor-returning-a-black-color-instead">LINK</a></p>
  
  <p>Then <strong><em>how can one set the background image for a <code>SKScene</code>? Please be as specific as possible, sample code would be great!</em></strong></p>