Introduce a utils module including python versions of MOM_define_layout and mpp_compute_extent functions. These are to be used to determine domain decomposition extents and whether NTASKS_OCN is feasible.
Add a check to buildnmi to inform the user if NTASKS_OCN is feasible.
Add auxiliary tools to generate an mask table, and to plot existing mask tables. These auxiliary tools require numpy, xarray, and matplotlib.