switch from LINEAR EOS to MDJWF :  - make tests of vertical mixing pkg more selective  - MDJWF EOS was not tested in any experiment.
switch from LINEAR EOS to MDJWF :
 - make tests of vertical mixing pkg more selective
 - MDJWF EOS was not tested in any experiment.

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