add copyright notices

makefile

src/Morton_shuffler.cpp

src/Morton_shuffler.hpp

src/NS.cpp

src/RMHD_converter.cpp

src/base.hpp

src/fftwf_tools.cpp

src/fftwf_tools.hpp

src/field_descriptor.cpp

src/field_descriptor.hpp

src/full.cpp

src/p3DFFT_to_iR.cpp

src/p3DFFT_to_iR.hpp

src/test_field_descriptor.cpp