* remove overloads with explicit buffer, now BufferPool is used
* added async versions for all reduce functions

use correct types for integral/sum outputs

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

cudev is used for new device layer

* converted it to Algorithm
* old API still can be used for source compatibility (marked as deprecated)

This reverts commit fba72cb6, reversing
changes made to 02131ffb.

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

#1713 Added the possibility of setting user_block_size manually for gpu::matchTemplate function (and gpu::convolve). Added a buffer param into these functions. Removed using of 2^n block sizes when it's not necessary.

fixed gpu module error reporting
added asynchronous version of some functions

moved crossCorr (as NPP_Staging wrapper) into public GPU module part from the internal matchTemplate files