In save_quality_control --> allow to output a specific slice by giving index_list
In save_quality_control --> allow to output a specific slice by giving index_list


Former-commit-id: 795cadd68c1b0f0c69d31c8cba3dd2a2b36918e8
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox