Removed old netcdf libraries on Hexagon Feb. 11th

Old netcdf-pgi-cnl and netcdf-pathscale-cnl modules have been removed from the module list on Hexagon.

Use instead Crays version, available as module netCDF, or netcdf-cnl which we have compiled.

Both netCDF and netcdf-cnl checks which PrgEnv you have loaded, and loads the appropriate version.

netcdf-cnl/4.0 is currently not netcdf4 enabled.