title: SWT components relayout after visibility set to false
body: <p>Lets say if I have a <code>GridLayout</code> composite with column = 1. (Something like a vertical flow layout)</p>
  
  <p>I have added Label 1, Label 2, Label 3 to this composite, and they will appear accordingly.</p>
  
  <pre><code>----------
  Label 1  |
  Label 2  |
  Label 3  |
  ----------
  </code></pre>
  
  <p>So is it possible that if I set the visibility of Label 2 to be <code>false</code>, can Label 3 move up to replace Label 2? And if Label 2 visibility is set back to <code>true</code>, Label 3 will move down?</p>