Serialization

• clean a bit NodeBase class.
• wip serialization of NodeBase that exemplify the 'intrusive' serialization (Serializer class member) + test.
• wip serialization of Eigen types (binary only) + test.
• serialization TimeStamp + test.
• serialization entry-point object is referred by typeid.

src/test/serialization/cereal/gtest_serialization_eigen_sparse.cpp

@@ -12,7 +12,6 @@
 
 #include "../../../serialization/cereal/io.h"
 
-#include <cereal/types/memory.hpp>
 #include <fstream>
 
 class WolfTestCerealSerializationEigenSparse : public testing::Test