title: Why does Leading/Trailing space show as -16?
body: <p>As I updated my Xcode from version 5 to 6 I saw a strange things in the storyboard. Here is one example:</p>
  
  <ul>
  <li>What my requirement was - I wanted no space between my view and the container view.</li>
  <li>What I did - I dragged the views left/right edge so that it meets the container margin. And then I put a horizontal spacing constraint.</li>
  </ul>
  
  <p>Earlier the value used to be -
  Leading/Trailing Space to:Superview Equals:0</p>
  
  <p>Now after updating to Xcode 6 it always shows -
  Leading/Trailing Space to:Superview Equals:-16.000000</p>
  
  <p>Why does this happen? </p>