title: How to set UIViewController "extend edges" properties
body: <p>I see the following selections in Storyboard for extending the edges of a UIViewController's view under navBars/tabBars:</p>
  
  <p><img src="https://i.stack.imgur.com/eU64M.png" alt="enter image description here"></p>
  
  <p>But how do I set these properties globally for all of my ViewControllers in code? As opposed to manually checking/unchecking on every ViewController in Storyboard. </p>