Merge branch 'devel' into release/1.4.0

CHANGELOG.md

CMakeLists.txt

include/ndcurves/bezier_curve.h

include/ndcurves/constant_curve.h

include/ndcurves/cubic_hermite_spline.h

include/ndcurves/curve_abc.h

include/ndcurves/fwd.h

include/ndcurves/helpers/effector_spline_rotation.h

include/ndcurves/linear_variable.h

include/ndcurves/optimization/details.h

include/ndcurves/piecewise_curve.h

include/ndcurves/polynomial.h

include/ndcurves/se3_curve.h

include/ndcurves/serialization/curves.hpp

include/ndcurves/serialization/registeration.hpp

include/ndcurves/sinusoidal.h

include/ndcurves/so3_linear.h

include/ndcurves/so3_smooth.h

python/ndcurves/curves_python.cpp

python/ndcurves/python_variables.h