title: UIEdgeInsets not working
body: <p>I want the button text to appear near the middle of the button, in the x-dimension. Yet the button text still remains on the far left of the view, as if <code>x</code> were <code>0</code>. I've made sure to <code>setTitleEdgeInsets</code> and <code>setContentHorizontalAlignment</code>. I also tried setting the <code>contentEdgeInsets</code> instead of the <code>titleEdgeInsets</code>. What have I missed?   </p>
  
  <pre><code>UIButton *row = [[UIButton alloc] initWithFrame:
                   CGRectMake(0, index * kRowHeight, 320, kRowHeight)];
  [row setTitle:value forState:UIControlStateNormal];
  [row setContentHorizontalAlignment:UIControlContentHorizontalAlignmentLeft];
  [row setContentVerticalAlignment:UIControlContentVerticalAlignmentCenter];
  [row setTitleEdgeInsets:UIEdgeInsetsMake(180.0, 20.0, 0, 0)];
  [self.view addSubview:row];
  </code></pre>