core: Add core module for shared code
This commit also makes log4cxx dependency required
diff --git a/core/chronoshare-common.hpp b/core/chronoshare-common.hpp
new file mode 100644
index 0000000..44b5873
--- /dev/null
+++ b/core/chronoshare-common.hpp
@@ -0,0 +1,52 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2016, Regents of the University of California.
+ *
+ * This file is part of ChronoShare, a decentralized file sharing application over NDN.
+ *
+ * ChronoShare is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * ChronoShare 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 General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License along with
+ * ChronoShare, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ChronoShare authors and contributors.
+ */
+
+#ifndef CHRONOSHARE_CORE_COMMON_HPP
+#define CHRONOSHARE_CORE_COMMON_HPP
+
+#include "core/chronoshare-config.hpp"
+
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+#include <functional>
+#include <limits>
+#include <memory>
+#include <stdexcept>
+#include <string>
+#include <type_traits>
+#include <unistd.h>
+
+#include <boost/assert.hpp>
+#include <boost/concept_check.hpp>
+#include <boost/exception/all.hpp>
+#include <boost/noncopyable.hpp>
+#include <boost/throw_exception.hpp>
+
+namespace ndn {
+namespace chronoshare {
+
+using std::shared_ptr;
+using std::make_shared;
+
+} // chronoshare
+} // ndn
+
+#endif // CHRONOSHARE_CORE_COMMON_HPP