NEW: Slice instance has now 2 arguments per segmentation : WM and GM
NEW: Slice instance has now 2 arguments per segmentation : WM and GM

Former-commit-id: 43ab9d81f6d522455ea1e74cfeeea64b11c26c3a [formerly cc8468f11d58cba56c58fdb2606051860948b8b9]
Former-commit-id: 9916bad6a1b00bd6bcc7baf8e27858ddbd6784d2
Former-commit-id: eb64e1d5f49da6122b8735d2bbe6c743cebcbbe9
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox