o modif to fill a diagnostics using a scaling factor and a fraction-weight       field ; does not affect diagnostics_fill.F arguments.
o modif to fill a diagnostics using a scaling factor and a fraction-weight
      field ; does not affect diagnostics_fill.F arguments.

altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h