Fix 500s when requesting json after logged out:

* Update permissions decorator to make sure user is logged in first, else 401
* Stop further ajax json calls on failure

app/assets/javascripts/updateContent.js

@@ -26,7 +26,7 @@
     ).done(
       response => flushQueue(queue, response)
     ).fail(
-      () => clearQueue(queue)
+      () => poll = function(){}
     );
 
     setTimeout(