Copy specified HDF5 group from the ICs to output snapshot files

doc/RTD/source/ParameterFiles/parameter_description.rst

examples/main.c

examples/parameter_example.yml

src/Makefile.am

src/distributed_io.c

src/engine.c

src/engine.h

src/hdf5_object_to_blob.c

src/hdf5_object_to_blob.h

src/ic_info.c

src/ic_info.h

src/parallel_io.c

src/parallel_io.h

src/serial_io.c

src/serial_io.h

src/single_io.c

src/single_io.h

src/swift.h