+ OwningVector, and other cleanup in view of pybind11

Base/Axis/PointwiseAxis.cpp

@@ -20,6 +20,8 @@
 
 const size_t min_axis_size = 2;
 
+PointwiseAxis::~PointwiseAxis() = default;
+
 PointwiseAxis* PointwiseAxis::clone() const
 {
     return new PointwiseAxis(axisName(), m_coordinates);