title: Add/remove (in)active class from Bootstrap Collapse plugin's headings
body: <p>I'm wrestling a bit with the collapse JS from bootstrap. On my website I want to use the collapse to display some content. I want, whenever the user clicks on the heading to apply the class "active" to it. It already starts out with the class "inactive". So from inactive it goes to active when you click on it. On the other hand, it should when you re-click the same heading also change back to inactive. Which is currently not what it does now.</p>
  
  <p>Here is the JSfiddle: <a href="http://jsfiddle.net/Malachute/tZeT8/1/" rel="nofollow">http://jsfiddle.net/Malachute/tZeT8/1/</a>  Don't mind the collapse not working, that's working on my end and bad copied into JSfiddle.</p>