Integrate fft matlab demo scripts into matfaust.demo namespace.

gen_doc/CMakeLists.txt

misc/demo/FFT/BitReversalPermutation.m

misc/demo/FFT/CooleyTukeyFact.m

misc/demo/FFT/TransStockhamFact.m

misc/demo/FFT/dvp_complete.m

wrapper/matlab/+matfaust/+demo/+fft/BitReversalPermutation.m

wrapper/matlab/+matfaust/+demo/+fft/CooleyTukeyFact.m

wrapper/matlab/+matfaust/+demo/+fft/TransStockhamFact.m

wrapper/matlab/+matfaust/+demo/+fft/dvp_complete.m

wrapper/matlab/+matfaust/+demo/+fft/speed_up_fourier.m