NEW: added alto syn and bsplinesyn
NEW: added alto syn and bsplinesyn

Former-commit-id: 992d9a5c810851ba5febb8b9aceaf7a8c2568c56
Former-commit-id: e729076f3b19dea57900eca7af10e993466bceb7
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox