Start implementing fancy indexing for pyfaust.Faust.__getitem__().

src/faust_linear_operator/CPU/faust_MatDense.h

src/faust_linear_operator/CPU/faust_MatDense.hpp

src/faust_linear_operator/CPU/faust_MatSparse.h

src/faust_linear_operator/CPU/faust_MatSparse.hpp

src/faust_linear_operator/CPU/faust_TransformHelper.h

src/faust_linear_operator/CPU/faust_TransformHelper.hpp

src/faust_linear_operator/faust_MatGeneric.h

wrapper/python/pyfaust.py

wrapper/python/src/FaustCoreCpp.h

wrapper/python/src/FaustCoreCpp.hpp

wrapper/python/src/FaustCoreCy.pxd

wrapper/python/src/FaustCorePy.pyx