title: Make a CodeMirror editor and its gutter 100% height of container
body: <p>How do I make a CodeMirror editor and its gutter 100% of the height of its parent? </p>
  
  <p>For example, on jsfiddle, the editors have a 100% height gray gutter. </p>
  
  <p>I've gone through the CSS trying to make everything 100% height, but no effect. </p>