Add __tostring to lua.
%ignore tinyspline::DeBoorNet::operator=;
%ignore tinyspline::Domain::operator=;
+%rename (__tostring) tinyspline::BSpline::toString;
+%rename (__tostring) tinyspline::DeBoorNet::toString;
+%rename (__tostring) tinyspline::Domain::toString;
+
%rename("%(undercase)s", %$isfunction) "";
%rename("%(undercase)s", %$ismember, %$not %$isconstructor) "";
