OPT: added new labels along the spinal cord for straightening
OPT: added new labels along the spinal cord for straightening

Former-commit-id: de24b1065b48afe01e0bb420e8e5ea570590ad91 [formerly b48e71ea12ee0abea8af4d608c05a84a1c2c14ac]
Former-commit-id: 480f845d14c0cbb7c16c3505814436d85dd2654e
Former-commit-id: 6a6cd8a56be053fb8e4261d56189960b7d8c4810
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox