created common nav bar in footer, changed send feedback link

src/site/docs/tutorials/custom-elements/index.markdown

 ---
 layout: default
 title: "Target 8: Define a Custom DOM Tag"
 description: "Define a custom DOM element tag with help from the Web UI package"
 has-permalinks: true
 tutorial:
   id: web-components
+next: fetchdata
+next-title: "Fetch Data Dynamically"
+prev: templates
+prev-title: "Use <template>"
 ---
 
 {% capture whats_the_point %}
 
 * Make your own DOM element tags with the <element> tag.
 * A custom element requires a template and can have a script.
 * Use data binding to connect Dart variables to content.
 * Directly attach event handlers in HTML.
 
 {% endcapture %}
@@ skipping 377 matching lines @@
   and the corresponding source code.
 </li>
 <li>
   The Web UI package contains several examples,
   including a version of
   <a href="https://github.com/dart-lang/web-ui/tree/master/example/todomvc"
      target="_blank">TodoMVC</a>.
 </li>
 </ul>
 
-<hr>
-
-<div class="row">
-  <div class="span3">
-  <a href="/docs/tutorials/templates/"><i class="icon-chevron-left"> </i> Use &lt;template&gt;</a>
-  </div>
-  <div class="span3">
-<a href="http://code.google.com/p/dart/issues/entry?template=Tutorial%20feedback"
- target="_blank">
-<i class="icon-comment"> </i>
-Send feedback
-</a>
-  </div>
-  <div class="span3">
-  <a href="/docs/tutorials/fetchdata/" class="pull-right">Fetch Data Dynamically <i class="icon-chevron-right"> </i> </a>
-  </div>
-</div>
-
 {% endcapture %}
 
 {% include tutorial.html %}