ice-air coupling (LIM3). part1: snow blown by the winds

[clem]

In LIM3, a portion of the snow that falls on ice is considered to be blown away by the winds. It then falls in the ocean, and should be counted for in the fresh water budget of the ocean (emp_oce). It is done correctly in forced mode but not in coupled mode. Therefore emp_oce and emp_ice should be changed in sbccpl.F90 as follows:

! zsnw = snow percentage over ice after wind blowing
 zsnw(:,:) = 0._wp
 CALL lim_thd_snwblow( p_frld, zsnw )
      
! --- evaporation minus precipitation corrected for the effect of wind blowing on snow --- !
 zemp_oce(:,:) = zemp_tot(:,:) - zemp_ice(:,:) - zsprecip * (1._wp - zsnw)
 zemp_ice(:,:) = zemp_ice(:,:) + zsprecip * (1._wp - zsnw)

[clem]

solved at r6399