OPT: allow parser to parse without checking file existence and permissions
OPT: allow parser to parse without checking file existence and permissions

Former-commit-id: 040df0b9f6fb3169857773a89a4c00ce49bf34a0
Former-commit-id: 18868dc3f7e468ce6d5ecd98dd6220f7c11b33f3
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox