Introduce account document to user document

An account document is attached to a user document if an account of the
user is on the server. It may be missing if the user is on a remote server.

src/common/get-user-summary.ts

@@ -7,6 +7,6 @@ import { IUser } from '../api/models/user';
 export default function(user: IUser): string {
 	return `${user.name} (@${user.username})\n` +
 		`${user.posts_count}投稿、${user.following_count}フォロー、${user.followers_count}フォロワー\n` +
-		`場所: ${user.profile.location}、誕生日: ${user.profile.birthday}\n` +
+		`場所: ${user.account.profile.location}、誕生日: ${user.account.profile.birthday}\n` +
 		`「${user.description}」`;
 }