title: Bootstrap navbar search icon
body: <p>The bootstrap examples for the navbar search form have just a text box.</p>
  
  <p>I'd like to be able to add a search icon at the beginning, like Twitter does on their search box. How can I do this with bootstrap?</p>
  
  <p>Here's what I've tried so far but it's failing:
  <a href="http://jsfiddle.net/C4ZY3/3/" rel="noreferrer">http://jsfiddle.net/C4ZY3/3/</a></p>