title: add tooltip in stacked bar chart D3
body: <p>Could you please help me in adding tooltip in stacked Bar chart. I have created Fiddle <a href="http://jsfiddle.net/9UfT2/3/." rel="nofollow">Link</a></p>
  
  <p>i want to add tool tip on each bar chart ie. Each bar should show tool tip for each color. How can i do that.</p>
  
  <pre><code>&gt; NA
  </code></pre>
  
  <p>Thanks in advance</p>