Move totally Faust.rand() to FaustFactory.rand() and update API doc.

...r/matlab/+matfaust/@ConstraintGeneric/ConstraintGeneric.m

wrapper/matlab/+matfaust/@ConstraintInt/ConstraintInt.m

wrapper/matlab/+matfaust/@ConstraintMat/ConstraintMat.m

wrapper/matlab/+matfaust/@ConstraintReal/ConstraintReal.m

wrapper/matlab/+matfaust/@Faust/Faust.m

wrapper/matlab/+matfaust/@FaustFactory/FaustFactory.m

wrapper/matlab/+matfaust/@ParamsFact/ParamsFact.m

...matfaust/@ParamsHierarchicalFact/ParamsHierarchicalFact.m

...r/matlab/+matfaust/@StoppingCriterion/StoppingCriterion.m

wrapper/python/pyfaust.py