Add matlab wrapper for factorization algorithms (palm4msa and hierarchical fact.).

- Adding also unit tests for that wrapper.
- Adding doxy. doc. skeleton for that wrapper.
- Adjusting palm4msa unit tests (py. and c++, lambda mul. was missing).
- Extending mex C++ code for interfacing hierarchical_fact and palm4msa: they were not capable to transmit all StoppingCriterion attributes or init. factors (using always the default ones for hierarchical fact. algo.).
- Explicitely freeing the matlab-managed memory in getConstraint() (mx2Faust.hpp).
- Other related or minor changes.