revision and fix episode numbers

episodes can be checked and fixed. On checking errors and warnings are
displayed.  Once only warnings exist, episodes can be fixed.

website/agenda/planung/calendar.cgi

@@ -109,6 +109,7 @@ if (
             <!--<link href="css/theme.default.css" rel="stylesheet">-->
             <script src="js/jquery.tablesorter.min.js"></script>
             <script src="js/jquery.tablesorter.widgets.min.js"></script>
+            <style>#content{ top:5rem; position:relative; }</style>
         };
     }
 }