Network-related operations of the TorrentManager class

This commit adds the downloadTorrentFile, download_file_manifest, download_data_packet methods

Change-Id: Ie221bc07907eb58117e83e317eca578174142d6d
Refs: #3505
diff --git a/tests/unit-tests/unit-test-time-fixture.hpp b/tests/unit-tests/unit-test-time-fixture.hpp
new file mode 100644
index 0000000..d50f22f
--- /dev/null
+++ b/tests/unit-tests/unit-test-time-fixture.hpp
@@ -0,0 +1,71 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+* Copyright (c) 2016 Regents of the University of California.
+*
+* This file is part of the nTorrent codebase.
+*
+* nTorrent 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.
+*
+* nTorrent 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 nTorrent, e.g., in COPYING.md file. If not, see
+* <http://www.gnu.org/licenses/>.
+*
+* See AUTHORS for complete list of nTorrent authors and contributors.
+*/
+
+#ifndef NDN_TESTS_UNIT_TESTS_UNIT_TEST_TIME_FIXTURE_HPP
+#define NDN_TESTS_UNIT_TESTS_UNIT_TEST_TIME_FIXTURE_HPP
+
+#include <ndn-cxx/util/time-unit-test-clock.hpp>
+
+#include <boost/asio/io_service.hpp>
+
+namespace ndn {
+namespace ntorrent {
+namespace tests {
+
+class UnitTestTimeFixture
+{
+public:
+  UnitTestTimeFixture()
+    : steadyClock(make_shared<time::UnitTestSteadyClock>())
+    , systemClock(make_shared<time::UnitTestSystemClock>())
+  {
+    time::setCustomClocks(steadyClock, systemClock);
+  }
+
+  ~UnitTestTimeFixture()
+  {
+    time::setCustomClocks(nullptr, nullptr);
+  }
+
+  void
+  advanceClocks(const time::nanoseconds& tick, size_t nTicks = 1)
+  {
+    for (size_t i = 0; i < nTicks; ++i) {
+      steadyClock->advance(tick);
+      systemClock->advance(tick);
+
+      if (io.stopped())
+        io.reset();
+      io.poll();
+    }
+  }
+
+public:
+  shared_ptr<time::UnitTestSteadyClock> steadyClock;
+  shared_ptr<time::UnitTestSystemClock> systemClock;
+  boost::asio::io_service io;
+};
+
+} // namespace tests
+} // namespace ntorrent
+} // namespace ndn
+
+#endif // NDN_TESTS_UNIT_TESTS_UNIT_TEST_TIME_FIXTURE_HPP