fixed bug in global_z_level_ratio, z_level_ratio and zr_u/v that did not allow for levels to stretch (z_level ratio can now be >1 as before the introduction of global terrain)
fixed bug in global_z_level_ratio, z_level_ratio and zr_u/v that did not allow for levels to stretch (z_level ratio can now be >1 as before the introduction of global terrain)

gutmann/icar,NCAR/icar,NCAR/icar,gutmann/icar,NCAR/icar,gutmann/icar