NEW: compute the hausdorff distance if a reference seg is provided
NEW: compute the hausdorff distance if a reference seg is provided

Former-commit-id: fe47511efc40063d7a2fe8422a150dc87e68aeb7
Former-commit-id: 1638afa675bd5876c4f33feeb7dc4fbe92737b00
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox