ESMF setup that does cg on one PE set, several fg's on some other
PE's and has cg2fg and fg2cg that distribute and aggregate needed 
fields respectively

cg              - runs on one PE
fg's            - run on 16 PE's
cg2fg and fg2cg - run over all 17 PE's

MITgcm setup for cg is a 20x20x20 box with 2km grid 
resolution

MITgcm setup for fg's is a set of 25 20x1x20 non-hydrostatic slices 
100m grid resolution and a custom driver that switches between slices. 
For now all slices are assumed to have identical parameters and
bathymetry and only the the "pickup" state information
is switched by the custom driver.

run sequence is

   initialization
     :
     :
     :

   timestepping

    cg    &
    fg    &
     BARRIER
    cg2fg &
    fg2cg &
     BARRIER

   finish