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/web/app/common/scripts/streaming/othello.ts

@@ -5,7 +5,7 @@ import MiOS from '../../mios';
 export class OthelloStream extends Stream {
 	constructor(os: MiOS, me) {
 		super(os, 'othello', {
-			i: me.token
+			i: me.account.token
 		});
 	}
 }