[~] fixed warning in featuers2d under windows (can't generate assignment operator)

2) NVidia tests for GPU
3) FD sample that uses NVidia's interface.

fixed TargetArchs implementation in case when HAVE_CUDA=false, added initial structure for multi_gpu sample

2) added mask support to device 'transform' function 
3) sample hog gpu: waitKey(1) -> waitKey(3), in other case image is not displayed.

removed keypoint_matching.cpp from samples/cpp/CMakeLists.txt, fixed some crashes in select3dobj.cpp