Remove previously deprecated headers, methods, and constants

Change-Id: I3e809e25c8f2bc2ae0f027413d9e0161245353c6
Refs: #3988
diff --git a/src/encoding/oid.hpp b/src/encoding/oid.hpp
index 2f89484..2eea310 100644
--- a/src/encoding/oid.hpp
+++ b/src/encoding/oid.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).
  *
@@ -82,7 +82,6 @@
   void
   decode(CryptoPP::BufferedTransformation& in);
 
-
 private:
   bool
   equal(const Oid& oid) const;
@@ -91,11 +90,6 @@
   std::vector<int> m_oid;
 };
 
-/**
- * @deprecated Use Oid type instead
- */
-typedef Oid OID;
-
 namespace oid {
 // crypto algorithm
 extern const Oid RSA;