initial release
based on h5fortran, now including HDF5-MPI parallel read, write of datasets and attributes.
Nearly all of the object-oriented functionality from h5fortran is present in h5fortran-mpi.
A key distinction for user programs is h5fortran-mpi REQUIRES MPI to be linked in the user program, EVEN IF the program doesn't use HDF5-MPI.
At a future point, to fully merge h5fortran and h5fortran-mpi, we might consider a build-time way to remove the need to link MPI for HDF5/h5fortran programs not using HDF5-MPI.