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/transport/unix-transport.cpp b/src/transport/unix-transport.cpp
index f2e44aa..be5536e 100644
--- a/src/transport/unix-transport.cpp
+++ b/src/transport/unix-transport.cpp
@@ -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).
  *
@@ -23,7 +23,7 @@
 #include "stream-transport-impl.hpp"
 
 #include "../face.hpp"
-#include "util/face-uri.hpp"
+#include "net/face-uri.hpp"
 
 namespace ndn {
 
@@ -47,7 +47,7 @@
   }
 
   try {
-    const util::FaceUri uri(uriString);
+    const FaceUri uri(uriString);
 
     if (uri.getScheme() != "unix") {
       BOOST_THROW_EXCEPTION(Error("Cannot create UnixTransport from \"" +
@@ -58,7 +58,7 @@
       path = uri.getPath();
     }
   }
-  catch (const util::FaceUri::Error& error) {
+  catch (const FaceUri::Error& error) {
     BOOST_THROW_EXCEPTION(Error(error.what()));
   }