Remove previously deprecated headers, methods, and constants

Change-Id: I3e809e25c8f2bc2ae0f027413d9e0161245353c6
Refs: #3988
diff --git a/src/util/scheduler.hpp b/src/util/scheduler.hpp
index cad5c09..e3927ac 100644
--- a/src/util/scheduler.hpp
+++ b/src/util/scheduler.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2013-2016 Regents of the University of California.
+ * Copyright (c) 2013-2017 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -127,11 +127,6 @@
 class Scheduler : noncopyable
 {
 public:
-  /**
-   * \deprecated use EventCallback
-   */
-  typedef EventCallback Event;
-
   explicit
   Scheduler(boost::asio::io_service& ioService);