rename OBCS_CHECK_TOPOGRAPHY -> OBCS_CHECK_DEPTHS + call EXCH2_CHECK_DEPTHS
rename OBCS_CHECK_TOPOGRAPHY -> OBCS_CHECK_DEPTHS
+ call EXCH2_CHECK_DEPTHS

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