added /manage/ and /manage/accounts/ views, added TOC to template

templates/administration.jinja2

@@ -0,0 +1,23 @@
+{% extends "base.jinja2" %}
+
+{% block title %}Administrative tools — {{ app_name }}{% endblock %}
+
+{% block content %}
+<h1>Administrative tools</h1>
+
+{% if current_user and current_user.is_admin %}
+<ul>
+  <li>
+    <a href="/manage/export">Export pages</a>
+  </li>
+  <li>
+    <a href="/manage/import">Import pages</a>
+  </li>
+  <li>
+    <a href="/manage/accounts">Manage accounts</a>
+  </li>
+</ul>
+{% else %}
+<p>Administrative tools can be accessed by administrator users only.</p>
+{% endif %}
+{% endblock %}