Update pyfaust wrapper (constraint and param classes for facto.).

- Replace pyfaust.ConstraintScalar by pyfaust.ConstraintInt and ConstraintReal (like in matfaust).
- Reinforce the arguments checking in constructors of ConstraintInt, ConstraintReal, StoppingCriterion, ParamsHierarchicalFact, ParamsPalm4MSA.
- Other minor changes (including in matfaust).