v0.5

Main news:

1. Run with any number of MPI processes: now the number of MPI processes does not necessarily have to be an integer divisor of the number of sub-domains.
2. Use external MPICH compatible library (Intel MPI or whatever library is available on the HPC platform): needs to be set up (module load or whatever)
3. Added command line option (-c) to use NETCDF4_CLASSIC format for output (default format is NETCDF4).

Minor fixes and updates.

v0.4.1

Removed unnecessary numpy dependency.