Initial version of gridspec. Compliant with ESMF gridspec file definitions. Includes support for the following grids:
- gnomonic cubed-sphere (see:
gridspec-create gcs --help) - stretched gnomonic cubed-sphere (see:
gridspec-create sgcs --help) - regular lat-lon grid (see:
gridspec-create latlon --help)- pole-centered/polar-edge and dateline-centered/dateline-edge
- regional lat-lon grid