build: Reviving support for precompiled headers

This commit also includes an update of ./waf, which has several
improvements.  In particular, clang++ is now default compiler on OSX
platform.

This commit also includes reorganization of tests. All unit tests are
now under tests/unit-tests and integrated tests are under
tests/integrated.  This change allows small compilation optimization,
partially related to precompiled headers.

Change-Id: I4c171c04d18e9cb83e461264a35b9ed85ea4d50e
diff --git a/tests/unit-tests/transport/dummy-face.hpp b/tests/unit-tests/transport/dummy-face.hpp
new file mode 100644
index 0000000..fd724b0
--- /dev/null
+++ b/tests/unit-tests/transport/dummy-face.hpp
@@ -0,0 +1,116 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2014 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.
+ */
+
+#ifndef NDN_TESTS_UNIT_TESTS_TRANSPORT_DUMMY_FACE_HPP
+#define NDN_TESTS_UNIT_TESTS_TRANSPORT_DUMMY_FACE_HPP
+
+#include "face.hpp"
+#include "transport/transport.hpp"
+
+namespace ndn {
+
+class DummyTransport : public Transport
+{
+public:
+  void
+  receive(const Block& block)
+  {
+    m_receiveCallback(block);
+  }
+
+  virtual void
+  close()
+  {
+  }
+
+  virtual void
+  pause()
+  {
+  }
+
+  virtual void
+  resume()
+  {
+  }
+
+  virtual void
+  send(const Block& wire)
+  {
+    if (wire.type() == Tlv::Interest) {
+      m_sentInterests->push_back(Interest(wire));
+    }
+    else if (wire.type() == Tlv::Data) {
+      m_sentDatas->push_back(Data(wire));
+    }
+  }
+
+  virtual void
+  send(const Block& header, const Block& payload)
+  {
+    this->send(payload);
+  }
+
+public:
+  std::vector<Interest>* m_sentInterests;
+  std::vector<Data>*     m_sentDatas;
+};
+
+
+/** \brief a Face for unit testing
+ */
+class DummyFace : public Face
+{
+public:
+  explicit
+  DummyFace(shared_ptr<DummyTransport> transport)
+    : Face(transport)
+    , m_transport(transport)
+  {
+    m_transport->m_sentInterests = &m_sentInterests;
+    m_transport->m_sentDatas     = &m_sentDatas;
+  }
+
+  /** \brief cause the Face to receive a packet
+   */
+  template<typename Packet>
+  void
+  receive(const Packet& packet)
+  {
+    m_transport->receive(packet.wireEncode());
+  }
+
+public:
+  std::vector<Interest> m_sentInterests;
+  std::vector<Data>     m_sentDatas;
+
+private:
+  shared_ptr<DummyTransport> m_transport;
+};
+
+inline shared_ptr<DummyFace>
+makeDummyFace()
+{
+  return make_shared<DummyFace>(make_shared<DummyTransport>());
+}
+
+} // namespace ndn
+
+#endif // NDN_TESTS_UNIT_TESTS_TRANSPORT_DUMMY_FACE_HPP