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/Rating.js

@@ -0,0 +1,52 @@
+import { EventBus, Events } from './EventBus'
+import { UnitOfWorkTracker } from '../mixins/UnitOfWorkTracker'
+import { thenVoteComment } from '../../api/comments'
+const TEMPLATE = `
+<div class="comment-rating"
+    :class="{rated: hasRating, positive: isPositive }"
+    >
+    <div class="comment-rating-value" title="Number of likes">{{ rating }}</div>
+    <div class="comment-action-rating up" title="Like comment"
+        v-if="canVote"
+        @click="upVote"
+    />
+</div>
+`;
+
+Vue.component('comment-rating', {
+    template: TEMPLATE,
+    mixins: [UnitOfWorkTracker],
+    props: {comment: Object},
+    computed: {
+        positiveRating() {
+            return this.comment.properties.rating_positive || 0;
+        },
+        negativeRating() {
+            return this.comment.properties.rating_negative || 0;
+        },
+        rating() {
+            return this.positiveRating - this.negativeRating;
+        },
+        isPositive() {
+            return this.rating > 0;
+        },
+        hasRating() {
+            return (this.positiveRating || this.negativeRating) !== 0;
+        },
+        canVote() {
+            return this.comment.user.id !== pillar.utils.getCurrentUser().user_id;
+        }
+    },
+    methods: {
+        upVote() {
+            let vote = this.comment.current_user_rating === true ? 0 : 1; // revoke if set
+            this.unitOfWork(
+                thenVoteComment(this.comment.parent, this.comment.id, vote)
+                .then((updatedComment) => {
+                    EventBus.$emit(Events.UPDATED_COMMENT, updatedComment);
+                })
+                .fail((err) => {toastr.error(pillar.utils.messageFromError(err), 'Faied to vote on comment')})
+            );
+        }
+    }
+});