Port additional changes to popover docs

https://github.com/twbs/bootstrap/commit/43b7a942bc4eb2307353dcf32e7c245664546afc
So all the popover demos work great.
/fyi @mdo

javascript/index.html

@@ -1221,8 +1221,8 @@
 <div class="highlight"><pre><code class="html"><span class="nt">&lt;button</span> <span class="na">type=</span><span class="s">&quot;button&quot;</span> <span class="na">class=</span><span class="s">&quot;btn btn-lg btn-danger&quot;</span> <span class="na">data-toggle=</span><span class="s">&quot;popover&quot;</span> <span class="na">title=</span><span class="s">&quot;Popover title&quot;</span> <span class="na">data-content=</span><span class="s">&quot;And here&#39;s some amazing content. It&#39;s very engaging. Right?&quot;</span><span class="nt">&gt;</span>Click to toggle popover<span class="nt">&lt;/button&gt;</span></code></pre></div>
 
   <h4>Four directions</h4>
-  <div class="bs-example tooltip-demo">
-    <div class="bs-example-tooltips">
+  <div class="bs-example popover-demo">
+    <div class="bs-example-popovers">
       <button type="button" class="btn btn-default" data-container="body" data-toggle="popover" data-placement="left" data-content="Vivamus sagittis lacus vel augue laoreet rutrum faucibus.">
         Popover on left
       </button>