COM: old function sct_get_centerline_from_labels that uses old scripts (independent fitting and then concatenation)
COM: old function sct_get_centerline_from_labels that uses old scripts (independent fitting and then concatenation)

Former-commit-id: 4a9a79f6140d745543029f5f3564d6536c75e3b1 [formerly 08d3d611d4d693fb5b275a1aa0b920e6a68502dc]
Former-commit-id: 08a5e1cafab0554bb9f442198fc1f08d1d971c6c
Former-commit-id: 6f1a2bbcdbdceb298068f3c88fe6a18bd71a96c0
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox