o add new parameter: sideDragFactor to enable half-slip-side BC   and change side-drag S/R to use viscosity from mom_calc_visc   (can switch back by setting sideDragFactor=0.); affects results at   truncation level; regenerate output for exp.: global_ocean.cs32x10(x3),    global_ocean_ebm, global_ocean_pressure, matrix_example & MLAdjust(x5).
o add new parameter: sideDragFactor to enable half-slip-side BC
  and change side-drag S/R to use viscosity from mom_calc_visc
  (can switch back by setting sideDragFactor=0.); affects results at
  truncation level; regenerate output for exp.: global_ocean.cs32x10(x3),
   global_ocean_ebm, global_ocean_pressure, matrix_example & MLAdjust(x5).

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