OPT: sct_asman: compute & save/load model : works only with compute model for now
OPT: sct_asman: compute & save/load model : works only with compute model for now

Former-commit-id: 4c91c771c2d5ad3dc277cebb3edb94736be53e4e
Former-commit-id: 6dd51159989c9aa257fd529d37e6b6df111cc337
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox