Initial commit of a log capture and reporting feature

This adds a new section to the admin panel called "Activity", that
supplies charts, graphs and details about messages entering and leaving
the host.

A new daemon captures details of system mail activity by monitoring
the /var/log/mail.log file, summarizing it into a sqllite database
that's kept in user-data.

management/templates/index.html

@@ -109,6 +109,7 @@
             </li>
             <li><a href="#sync_guide" onclick="return show_panel(this);">Contacts/Calendar</a></li>
             <li><a href="#web" onclick="return show_panel(this);">Web</a></li>
+            <li><a href="/admin/reports/" onclick="return api_credentials[0]!=''">Activity</a></li>
           </ul>
           <ul class="nav navbar-nav navbar-right">
             <li><a href="#" onclick="do_logout(); return false;" style="color: white">Log out</a></li>