Post follow and updates notifications V1 (#111)

* It is now possible to follow a post in order to receive updates about it
* Notifications are now sent when updates are published
* Post status changes are now tracked
* Update sidebar now shows the post status history
* Mark a comment as a post update using the comment form
* ... more ...

app/javascript/components/Comments/NewComment.tsx

@@ -1,6 +1,8 @@
 import * as React from 'react';
 import Gravatar from 'react-gravatar';
 
+import NewCommentUpdateSection from './NewCommentUpdateSection';
+
 import Button from '../shared/Button';
 import Spinner from '../shared/Spinner';
 import { DangerText } from '../shared/CustomTexts';
@@ -8,24 +10,34 @@ import { DangerText } from '../shared/CustomTexts';
 interface Props {
   body: string;
   parentId: number;
+  postUpdateFlagValue: boolean;
   isSubmitting: boolean;
   error: string;
   handleChange(e: React.FormEvent): void;
-  handleSubmit(body: string, parentId: number): void;
+  handlePostUpdateFlag(): void;
+  handleSubmit(
+    body: string,
+    parentId: number,
+    isPostUpdate: boolean
+  ): void;
 
   isLoggedIn: boolean;
+  isPowerUser: boolean;
   userEmail: string;
 }
 
 const NewComment = ({
   body,
   parentId,
+  postUpdateFlagValue,
   isSubmitting,
   error,
   handleChange,
+  handlePostUpdateFlag,
   handleSubmit,
 
   isLoggedIn,
+  isPowerUser,
   userEmail,
 }: Props) => (
   <React.Fragment>
@@ -33,18 +45,29 @@ const NewComment = ({
       {
         isLoggedIn ?
           <React.Fragment>
-            <Gravatar email={userEmail} size={36} className="currentUserAvatar" />
-            <textarea
-              value={body}
-              onChange={handleChange}
-              placeholder="Leave a comment"
-              className="newCommentBody"
-            />
-            <Button
-              onClick={() => handleSubmit(body, parentId)}
-              className="submitCommentButton">
-              { isSubmitting ? <Spinner color="light" /> : 'Submit' }
-            </Button>
+            <div className="commentBodyForm">
+              <Gravatar email={userEmail} size={48} className="currentUserAvatar" />
+              <textarea
+                value={body}
+                onChange={handleChange}
+                placeholder="Leave a comment"
+                className="newCommentBody"
+              />
+              <Button
+                onClick={() => handleSubmit(body, parentId, postUpdateFlagValue)}
+                className="submitCommentButton">
+                { isSubmitting ? <Spinner color="light" /> : 'Submit' }
+              </Button>
+            </div>
+            {
+              isPowerUser && parentId == null ?
+                <NewCommentUpdateSection
+                  postUpdateFlagValue={postUpdateFlagValue}
+                  handlePostUpdateFlag={handlePostUpdateFlag}
+                />
+              :
+                null
+            }
           </React.Fragment>
         :
           <a href="/users/sign_in" className="loginInfo">You need to log in to post comments.</a>