title: Unpin Twitter bootstrap's affix on scroll
body: <p>I'm using Twitter bootstrap's affix on a sidebar, on a traditional website layout (header -content and sidebar - footer).</p>
  
  <p>On a certain scroll point I want it to unpin from the page and return to it's original position:static, so it doesn't overlap the footer. I was trying to fiddle it around only with CSS, but since the .affix sets the element position as fixed it messes up the sidebar height. </p>
  
  <p>I'm thinking it has something to do with JS, maybe removing the affix class. Any solutions/suggestions?</p>