add CPP option USE_OLD_EXTERNAL_FORCING (default is undef) to use  EXTERNAL_FORCING_U,V,T,S subroutines (for backward compatibility).
add CPP option USE_OLD_EXTERNAL_FORCING (default is undef) to use
 EXTERNAL_FORCING_U,V,T,S subroutines (for backward compatibility).

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