Make header and footer divs actually <header> and <footer>

boards/static/css/md/base_page.css

@@ -124,14 +124,14 b' body {'
     max-width: 30em;
 }
 
-.header {
+header.navigation_panel {
     border-bottom: solid 2px #ccc;
     margin-bottom: 5px;
     border-top: none;
     margin-top: 0;
 }
 
-.footer {
+footer.navigation_panel {
     border-top: solid 2px #ccc;
     margin-top: 5px;
     border-bottom: none;

boards/templates/boards/base.html

@@ -28,7 +28,7 b''
       data-update-script="{% static 'js/updates.js' %}">
     <script src="{% static 'js/jquery-2.2.0.min.js' %}"></script>
 
-    <div class="navigation_panel header">
+    <header class="navigation_panel">
         <a class="link" href="{% url 'index' %}">{% trans "All threads" %}</a>
         {% if tags_str %}
         <a href="{% url 'index' %}?filter=fav_tags" title="{% trans "interesting" %}">★</a>,
@@ -58,7 +58,7 b''
         {% endif %}
 
         <a class="right-link link" href="{% url 'settings' %}">{% trans 'Settings' %}</a>
-    </div>
+    </header>
 
     <div id="fav-panel"><div class="post">{% trans "Loading..." %}</div></div>
 
@@ -75,7 +75,7 b''
     <script src="{% static 'js/refpopup.js' %}"></script>
     <script src="{% static 'js/main.js' %}"></script>
 
-    <div class="navigation_panel footer">
+    <footer class="navigation_panel">
         {% block metapanel %}{% endblock %}
         {% if rss_url %}
             [<a href="{{ rss_url }}">RSS</a>]
@@ -86,7 +86,7 b''
             {% blocktrans %}Speed: {{ ppd }} posts per day{% endblocktrans %}
         {% endwith %}
         <a class="link" href="#top" id="up">{% trans 'Up' %}</a>
-    </div>
+    </footer>
 
 </body>
 </html>