Move non-public classes and functions to psync::detail namespace

CompressionScheme, CompressionError, and MissingDataInfo, which are
public types, are instead moved to a new header PSync/common.hpp

Change-Id: If1b8cb037cb321ff32c080c67df9dc3689223c00
diff --git a/tests/test-state.cpp b/tests/test-state.cpp
index 3f04c8b..0e31a67 100644
--- a/tests/test-state.cpp
+++ b/tests/test-state.cpp
@@ -24,8 +24,7 @@
 #include <ndn-cxx/data.hpp>
 
 namespace psync {
-
-using namespace ndn;
+namespace detail {
 
 BOOST_AUTO_TEST_SUITE(TestState)
 
@@ -36,17 +35,14 @@
   state.addContent(ndn::Name("test2"));
 
   // Simulate getting buffer content from segment fetcher
-  Data data;
+  ndn::Data data;
   data.setContent(state.wireEncode());
   ndn::Buffer buffer(data.getContent().value_size());
   std::copy(data.getContent().value_begin(),
             data.getContent().value_end(),
             buffer.begin());
 
-  ndn::ConstBufferPtr bufferPtr = make_shared<ndn::Buffer>(buffer);
-
-  ndn::Block block(std::move(bufferPtr));
-
+  ndn::Block block(std::make_shared<ndn::Buffer>(buffer));
   State rcvdState;
   rcvdState.wireDecode(block);
 
@@ -58,16 +54,14 @@
   State state;
 
   // Simulate getting buffer content from segment fetcher
-  Data data;
+  ndn::Data data;
   data.setContent(state.wireEncode());
   ndn::Buffer buffer(data.getContent().value_size());
   std::copy(data.getContent().value_begin(),
             data.getContent().value_end(),
             buffer.begin());
-  ndn::ConstBufferPtr bufferPtr = make_shared<ndn::Buffer>(buffer);
 
-  ndn::Block block(std::move(bufferPtr));
-
+  ndn::Block block(std::make_shared<ndn::Buffer>(buffer));
   BOOST_CHECK_NO_THROW(State state2(block));
 
   State state2(block);
@@ -90,4 +84,5 @@
 
 BOOST_AUTO_TEST_SUITE_END()
 
+} // namespace detail
 } // namespace psync