Add the new matrix type MatBSR with its uncompleted test (test_MatBSR).

misc/test/CMakeLists.txt

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

src/faust_linear_operator/CPU/faust_MatBSR.h

src/faust_linear_operator/CPU/faust_MatBSR.hpp

src/faust_linear_operator/CPU/faust_MatDense.h

src/faust_linear_operator/CPU/faust_MatSparse.h

src/faust_linear_operator/CPU/faust_Vect.h

src/faust_linear_operator/faust_MatGeneric.h

src/faust_linear_operator/faust_MatGeneric.hpp

src/faust_linear_operator/faust_constant.h.in