add tri_sp constraint

src/algorithm/constraint/faust_ConstraintGeneric.h

src/algorithm/constraint/faust_ConstraintGeneric.hpp

src/algorithm/constraint/faust_ConstraintInt.hpp

src/algorithm/constraint/faust_ConstraintType.h

src/algorithm/constraint/faust_prox_gen.h

src/algorithm/constraint/faust_prox_gen.hpp

src/algorithm/factorization/faust_Palm4MSA.h

src/algorithm/factorization/faust_Palm4MSA.hpp

src/faust_linear_operator/CPU/faust_prox.h

src/faust_linear_operator/CPU/faust_prox.hpp

wrapper/python/pyfaust/factparams.py

wrapper/python/pyfaust/proj.py

wrapper/python/src/FaustFact.hpp