Conflicts:
	modules/core/include/opencv2/core/cuda.hpp
	modules/cudacodec/src/thread.cpp
	modules/cudacodec/src/thread.hpp
	modules/superres/perf/perf_superres.cpp
	modules/superres/src/btv_l1_cuda.cpp
	modules/superres/src/optical_flow.cpp
	modules/videostab/src/global_motion.cpp
	modules/videostab/src/inpainting.cpp
	samples/cpp/stitching_detailed.cpp
	samples/cpp/videostab.cpp
	samples/gpu/stereo_multi.cpp

* switch to InputArray/OutputArray
* add Stream support

Made all STL usages explicit to be able automatically find all usages of
particular class or function.

minor fixes and refactoring of GPU module

added assertion after all kernels calls

refactored gpu module.

avoid extra gpu memory allocation in BP and CSBP

some refactoring
added gpu module to compilation

added cuda_shared.hpp header was reorganized in order to speed up compilation