mgmt: declare the constructor of FaceMonitor explicit

Also fix the copyright notice at the top of the header file.

Change-Id: I01f4da97109652a8b1540aa57a57f67fa56a193d
diff --git a/src/mgmt/nfd/face-monitor.cpp b/src/mgmt/nfd/face-monitor.cpp
new file mode 100644
index 0000000..1331b09
--- /dev/null
+++ b/src/mgmt/nfd/face-monitor.cpp
@@ -0,0 +1,39 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2017 Regents of the University of California,
+ *                         Arizona Board of Regents,
+ *                         Colorado State University,
+ *                         University Pierre & Marie Curie, Sorbonne University,
+ *                         Washington University in St. Louis,
+ *                         Beijing Institute of Technology,
+ *                         The University of Memphis.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#include "face-monitor.hpp"
+
+namespace ndn {
+namespace nfd {
+
+FaceMonitor::FaceMonitor(Face& face)
+  : NotificationSubscriber<FaceEventNotification>(face, "ndn:/localhost/nfd/faces/events")
+{
+}
+
+} // namespace nfd
+} // namespace ndn