net: move network-related files to src/net

Some namespaces are changed:

* ndn::util::FaceUri is now ndn::FaceUri
* ndn::util::ethernet is now ndn::ethernet
* ndn::util::NetworkMonitor and related classes are now in ndn::net

refs #3940

Change-Id: Ia4754caef9726efc73f5a303cec46fc95c744d70
diff --git a/src/net/network-monitor.cpp b/src/net/network-monitor.cpp
new file mode 100644
index 0000000..c4a2e2e
--- /dev/null
+++ b/src/net/network-monitor.cpp
@@ -0,0 +1,65 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2017 Regents of the University of California.
+ *
+ * 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.
+ *
+ * @author Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ * @author Davide Pesavento <davide.pesavento@lip6.fr>
+ */
+
+#include "network-monitor.hpp"
+#include "ndn-cxx-config.hpp"
+
+#if defined(NDN_CXX_HAVE_OSX_FRAMEWORKS)
+#include "detail/network-monitor-impl-osx.hpp"
+#elif defined(NDN_CXX_HAVE_RTNETLINK)
+#include "detail/network-monitor-impl-rtnl.hpp"
+#else
+#include "detail/network-monitor-impl-noop.hpp"
+#endif
+
+namespace ndn {
+namespace net {
+
+NetworkMonitor::NetworkMonitor(boost::asio::io_service& io)
+  : m_impl(make_unique<Impl>(*this, io))
+{
+}
+
+NetworkMonitor::~NetworkMonitor() = default;
+
+uint32_t
+NetworkMonitor::getCapabilities() const
+{
+  return m_impl->getCapabilities();
+}
+
+shared_ptr<NetworkInterface>
+NetworkMonitor::getNetworkInterface(const std::string& ifname) const
+{
+  return m_impl->getNetworkInterface(ifname);
+}
+
+std::vector<shared_ptr<NetworkInterface>>
+NetworkMonitor::listNetworkInterfaces() const
+{
+  return m_impl->listNetworkInterfaces();
+}
+
+} // namespace net
+} // namespace ndn