common: remove DECL_FINAL/OVERRIDE macros; use C++11 keywords directly

Change-Id: I71a148b0df7c95387b2caa8e2b9fe93b03ca2399
Refs: #3599
diff --git a/tools/ndn-autoconfig/guess-from-search-domains.hpp b/tools/ndn-autoconfig/guess-from-search-domains.hpp
index e2eaa5a..bcfd4c8 100644
--- a/tools/ndn-autoconfig/guess-from-search-domains.hpp
+++ b/tools/ndn-autoconfig/guess-from-search-domains.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2014-2015,  Regents of the University of California,
+ * Copyright (c) 2014-2016,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -57,7 +57,7 @@
                          const NextStageCallback& nextStageOnFailure);
 
   virtual void
-  start() DECL_OVERRIDE;
+  start() override;
 };
 
 } // namespace autoconfig