title: CALayer - CABasicAnimation not scaling around center/anchorPoint
body: <p>Using the code below I've been trying to get my CALayer to scale around its center - but it scales by left/top (0,0). I saw this question: <a href="https://stackoverflow.com/questions/6379648/anchor-point-in-calayer">Anchor Point in CALayer</a> and have tried setting the anchorPoint - but it was [.5, .5] before I set it and setting makes no difference. Also tried setting <code>contentsGravity</code>.</p>
  
  <p>The set up is I have a <code>CAShapeLayer</code> added to <code>self.view.layer</code> I do some drawing in it and then add the CABasicAnimation. The animation runs fine - but it scales toward the top/left - not the center of the view.</p>
  
  <p>Have been tinkering with this for a few hours - it must be something simple but I'm not getting it.</p>
  
  <pre><code>shapeLayer.anchorPoint = CGPointMake(.5,.5);
  shapeLayer.contentsGravity = @"center";
  
  printf("anchorPoint %f  %f\n", shapeLayer.anchorPoint.x, shapeLayer.anchorPoint.y);
  
  CABasicAnimation *animation =
  [CABasicAnimation animationWithKeyPath:@"transform.scale"];
  
  animation.fromValue = [NSValue valueWithCATransform3D:CATransform3DIdentity];
  animation.toValue =   [NSValue valueWithCATransform3D:CATransform3DMakeScale(0.1, 0.1, 1.0)];
  
  [animation setDuration:1.0];
  animation.fillMode=kCAFillModeForwards;
  animation.removedOnCompletion=NO;
  [shapeLayer addAnimation:animation forKey:@"zoom"];
  </code></pre>