Add legal boilerplate and LICENSE file

src/app/services/websocket.service.ts

@@ -1,3 +1,6 @@
+// Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+// All Rights Reserved. See LICENSE file for details.
+
 import { Injectable } from '@angular/core';
 import { QueueingSubject } from 'queueing-subject';
 import { Observable } from 'rxjs/Observable';