Vue Comments: Comments ported to Vue + DnD fileupload

* Drag and drop files to comment editor to add a file attachment
* Using Vue to render comments

Since comments now has attachments we need to update the schemas
./manage.py maintenance replace_pillar_node_type_schemas

src/scripts/js/es6/common/utils/init.js

@@ -1 +1,35 @@
-export { transformPlaceholder } from './placeholder'
+export { transformPlaceholder } from './placeholder'
+export { prettyDate } from './prettydate'
+export { getCurrentUser, initCurrentUser } from './currentuser'
+
+
+export function debounced(fn, delay=1000) {
+    let timerId;
+    return function (...args) {
+      if (timerId) {
+        clearTimeout(timerId);
+      }
+      timerId = setTimeout(() => {
+        fn(...args);
+        timerId = null;
+      }, delay);
+    }
+  }
+
+/**
+ * Extracts error message from error of type String, Error or xhrError
+ * @param {*} err 
+ * @returns {String}
+ */
+export function messageFromError(err){
+  if (typeof err === "string") {
+    // type String
+    return err;
+  } else if(typeof err.message === "string") {
+    // type Error
+    return err.message;
+  } else {
+    // type xhr probably
+    return xhrErrorResponseMessage(err);
+  }
+}