Add circulant proj and a test, bind toeplitz and circ projs into matfaust and pyfaust.

misc/test/CMakeLists.txt

misc/test/src/C++/faust_circ.cpp.in

src/algorithm/constraint/faust_ConstraintGeneric.h

src/algorithm/constraint/faust_ConstraintMat.hpp

src/faust_linear_operator/CPU/faust_MatDense.hpp

src/faust_linear_operator/CPU/faust_prox.h

src/faust_linear_operator/CPU/faust_prox.hpp

...ab/+matfaust/+factparams/@ConstraintName/ConstraintName.m

wrapper/matlab/src/mexFaust.cpp.in

wrapper/python/pyfaust/factparams.py

wrapper/python/src/FaustFact.hpp