Load clipboard-support, if turned on

Note that the flag in the context must be named 'clipboard',
not 'clipboard.js'. This is because the dot is an illegal symbol in
variable names in twig.

templates/base.twig

@@ -28,5 +28,8 @@
 
     <!-- postload javascript -->
     <script type="text/javascript" src="/{{ baseurlpath }}resources/script.js"></script>
+    {% if clipboard %}
+    <script type="text/javascript" src="/{{ baseurlpath }}resources/clipboard.min.js"></script>
+    {% endif %}
     {% block postload %}{% endblock %}
 </body></html>