core: drop std::function and ndn::Exclude from common.hpp, add ndn::optional

Change-Id: Ie3983d8b6f9929430efd8ada8d942e3f95755cd4
diff --git a/rib/readvertise/client-to-nlsr-readvertise-policy.hpp b/rib/readvertise/client-to-nlsr-readvertise-policy.hpp
index af1481a..fd87360 100644
--- a/rib/readvertise/client-to-nlsr-readvertise-policy.hpp
+++ b/rib/readvertise/client-to-nlsr-readvertise-policy.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2014-2017,  Regents of the University of California,
+/*
+ * Copyright (c) 2014-2018,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -41,7 +41,7 @@
    *  If the route origin is "client" (typically from auto prefix propagation), readvertise it
    *  using the default signing identity.
    */
-  ndn::optional<ReadvertiseAction>
+  optional<ReadvertiseAction>
   handleNewRoute(const RibRouteRef& ribRoute) const override;
 
   time::milliseconds