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/vuecomponents/comments/EventBus.js

@@ -0,0 +1,7 @@
+export const Events = {
+    NEW_COMMENT: 'new-comment',
+    UPDATED_COMMENT: 'updated-comment',
+    EDIT_DONE: 'edit-done',
+    BEFORE_SHOW_EDITOR: 'before-show-editor'
+}
+export const EventBus = new Vue();