CUDA compilation in setup.py

setup.py script is now able to compile CUDA-code.
The script automatically find *.cu and *.cpp which are necessary to create the related dynamic library.

The compilation with CUDA-code has been tested by:
* changing HOG.cpp in HOG.cu
* using test_imagewindowiterator_hog_padding in menpo/image/test/image_features_test.py