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

fixed BFM warning ("cannot tell what pointer points to")

added assertion after all kernels calls

added mask support to SURF_GPU.

refactored gpu module, added vec math operators for uint, added support of 2 channel images into gpu::sum (removed support of double)

refactored transpose_gpu, made it non template function.

module reorganization: added folder with pure device functions, cuda_shared.hpp renamed to internal_shared.hpp

fixed compile error in transform.

added better threads configuration estimator for the minMax, minMaxLoc, countNonZero functions in gpu module