Bugfix for zlvs

[DeniseWorthen]

An optional array was recently added to allow Icepack to calculate fluxes relative to different atmosphere levels for different variables (eg "2m" temperatures and "10m" winds). This change was added to Icepack but the corresponding change to allocate and initialize this array were not made to CICE repository at the same time.

The branch for the most recent update to emc/develop was made in the intervening time when Icepack included the zlvs feature but CICE itself did not. After I realized this, I tested a branch with the zlvs change added to CICE and found that all answers changed. The zlvs allocation and initialization should be added to CICE since they are optionally used in Icepack.