old version isn't compiled with CUDA 5.5
new version doesn't depend on functional.hpp

This should allow many algorithms to take advantage of more parallelization
technologies.

initial optical flow was not cleaned during the second call

- added CMake toolchain file
- added WITH_NVCUVID flag

- new reduce implementation (with kepler optimizations)
- saturate_cast via asm command
- video SIMD instructions in element operations
- float arithmetics instead of double
- new deviceSupports function

- fixed printCudaDeviceInfo for new CC
- fixed some compilation errors and warnings
- removed unset command from CMake script
- removed unused std imports

GoodFeaturesToTrackDetector_GPU fails when no corners found