
- treat the case of very thin ice in 'evolution' branch. HEFF<1. _d -5
 implies that we instantaneoously melt the residual ice&snow.
- introduce SEAICE_CAP_ICELOAD. In cases when excessive
 an ice thickness introduces an excessive depletion of the
 (non-linear) free surface, on may use SEAICE_CAP_HEFF (only
 availble in legacy branch) to ultimately limit sIceLoad, or
 directly cap sIceLoad (using SEAICE_CAP_ICELOAD).

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