title: Rotating CAShapeLayer moves the position too
body: <p>I am creating a CAShapeLayer. I am adding rotation animation to it. Somehow transformation result is weird. The child layer is moving along with rotation. I need it to be in fixed center/position(anchor) and rotate. I know its messing up geometric transformation but i am unable to get it right. </p>
  
  <p>I have tried setting anchorpoint. I also followed this <a href="https://stackoverflow.com/questions/1968017/changing-my-calayers-anchorpoint-moves-the-view">post</a> </p>
  
  <p>Here is the code:</p>
  
  <pre><code>UIBezierPath *circle = [UIBezierPath bezierPathWithArcCenter:CGPointMake(75, 125)
                                                        radius:50
                                                    startAngle:0
                                                      endAngle:1.8 * M_PI
                                                     clockwise:YES];
  
  CAShapeLayer *circleLayer = [CAShapeLayer layer];
  [circleLayer setFrame:CGRectMake(200 - 50, 300 - 50, 100, 100)];
  circleLayer.path   = circle.CGPath;
  circleLayer.strokeColor = [UIColor orangeColor].CGColor;
  [circleLayer setFillColor:[UIColor clearColor].CGColor];
  circleLayer.lineWidth   = 3.0;
  
  if ([circleLayer animationForKey:@"SpinAnimation"] == nil) {
      CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
      animation.fromValue = [NSNumber numberWithFloat:0.0f];
      animation.toValue = [NSNumber numberWithFloat: 2 * M_PI];
      animation.duration = 10.0f;
      animation.repeatCount = INFINITY;
      animation.removedOnCompletion = NO;
      [circleLayer addAnimation:animation forKey:@"SpinAnimation"];
  }
  
  [self.view.layer addSublayer:circleLayer];
  </code></pre>