jointcal wraps a few methods on the wrong class (exposed by pybind11 2.2)

Also pybind11 2.2 does not allow one to specify both std::shared_ptr<Foo> and std::unique_ptr<Foo> as template parameters for py::class_ and this was being done for Gtransfo; fortunately none of the methods that use unique pointers was wrapped so I didn't have to add any workarounds.