Add an empty footer, to allow settings custom piwik like script per instance

umap/templates/base.html

@@ -70,5 +70,8 @@
             D.Event.on('.more_button', 'click', getMore);
         </script>
     {% endblock %}
+    {% block footer %}
+        {% include "umap/footer.html" %}
+    {% endblock footer %}
 </body>
 </html>