The sources for the H5hut library itself have been added to the external/ directory.
Restart with H5hut-io can be done similar to the classical restart:

mpiexec -n 4 ./iPic3D solinit GEM.inp

Note that 'solinit' is used instead of 'restart'. For this H5hut restarting method to work additional flags have been added to the input file.
See the examplpe in inpufiles/GEM.inp

2) Preprocessing tools that use H5hut-io were added to create new initial files and to test the library.

3) The postprocessing tool Xdmf in the postprocessing_tools/c++ directory creates an .xmf file that contains information to read the HDF5 solutions