FFT extended on CUDA,OpenMP. Created multiple tests and tutorial. FFT documentation extended on function description.
NMF extended on CUDA,OpenMP. Docummentation of NMF finnished. Tests and tutorial with description created. Shorted execution time of test.
Merge branch 'master' of github.com:JurajKabzan/viennacl-dev into JurajKabzan-master

Conflicts:
	tests/CMakeLists.txt
	viennacl/fft.hpp
Merge branch 'JurajKabzan-master'