Importaant: Corrected inert tracers (dye) output variable metadata

[arango]

Corrected the output variable long-name for output inert tracers. What ROMS computes in the age concentration and not the concentration mean age.

So we need to have:

    double dye_01(ocean_time, s_rho, eta_rho, xi_rho) ;
                    dye_01:long_name = "dye concentration, type 01" ;
                    dye_01:units = "kilogram meter-3" ;
                    dye_01:time = "ocean_time" ;
                    dye_01:coordinates = "x_rho y_rho s_rho ocean_time" ;
    double dye_01_age(ocean_time, s_rho, eta_rho, xi_rho) ;
                    dye_01_age:long_name = "age concentration, type 01" ;
                    dye_01_age:units = "second kilogram meter-3" ;
                    dye_01_age:time = "ocean_time" ;
                    dye_01_age:coordinates = "x_rho y_rho s_rho ocean_time" ;

instead of:

       double dye_01_age(ocean_time, s_rho, eta_rho, xi_rho) ;
                dye_01_age:long_name = "dye concentration mean age, type 01" ;
                dye_01_age:units = "second" ;
                dye_01_age:time = "ocean_time" ;
                dye_01_age:coordinates = "x_rho y_rho s_rho ocean_time" ;

So we corrected the output metadata for long_name. To compute the concentration mean age, we need to have dye_01_age/dye_01 during post-processing.

Many thanks to John Wilkin for bringing this to my attention.

I also corrected CPP typo in mod_stepping.F. We need to have ADJUST_BOUNDARY instead.