title: renderInContext does not capture rotated subviews
body: <p>A <code>UIImageVIew</code> (<code>imageView</code>) is added to <code>self.view</code>, capturing the view to album works perfectly:</p>
  
  <pre><code> CGSize size = CGSizeMake(self.view.frame.size.height, self.view.frame.size.width);
   UIGraphicsBeginImageContext(size);
   [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
   UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
   UIGraphicsEndImageContext();
   UIImageWriteToSavedPhotosAlbum(image, self, nil, nil);
  </code></pre>
  
  <p>However, if the <code>imageView</code> subview is rotated by:</p>
  
  <pre><code> [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
  </code></pre>
  
  <p>Capturing <code>self.view</code> again does not reflected the rotation. The subview <code>imageView</code> is as if not rotated.</p>
  
  <p>How to make <code>renderInContext</code> works with subviews rotated by <code>CABasicAnimation</code>?</p>
  
  <p>UPDATE:</p>
  
  <blockquote>
    <p>Warning: The CALayer/-renderInContext: method doesn't implement the
    full Core Animation composition model. The code provided below will be
    able to resolve most of the situations, but there are things that the
    CALayer/-renderInContext: method doesn't render correctly, so you may
    wish to contact Developer Technical Support for workaround requests.</p>
  </blockquote>
  
  <p>Official Apple Technical Q&amp;A <a href="http://developer.apple.com/library/ios/#qa/qa1703/_index.html" rel="noreferrer">QA1703</a> suggested to contact Developer Technical Support for workaround requests. </p>
  
  <p>Is there a workaround already existed?</p>