OPT: 2 changes have been made: -algo_fitting is now contained into the parameter param so that it can be changed when calling from a different script -for algo_fitting==hanning: x_centerline_fit, y_centerline_fit, z_centerline_fit were return as lists but  x_centerline_fit_deriv, y_centerline_fit_deriv, z_centerline_fit_deriv were return as array. Everything is now array as for algo_fitting==nurbs the outputs were all arrays.
OPT: 2 changes have been made:
-algo_fitting is now contained into the parameter param so that it can be changed when calling from a different script
-for algo_fitting==hanning: x_centerline_fit, y_centerline_fit, z_centerline_fit were return as lists but  x_centerline_fit_deriv, y_centerline_fit_deriv, z_centerline_fit_deriv were return as array. Everything is now array as for algo_fitting==nurbs the outputs were all arrays.

Former-commit-id: 131784492dca9e639c8fc400ae58ddafcd1c4ee6
Former-commit-id: c35a2452db72342ec191bb30d5e93304f90aad5a
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox