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

Python 3 requires METH_VARARGS | METH_KEYWORDS, not just METH_KEYWORDS.

This protects from unwanted implicit conversions between types at compile time.

Also, removed the one from modules/python/src2/cv.py and cleared its
executable bit, since it's not a script.

* Drop some low level API
* Remove outdated overloads
* Utilize Input/OutputArray

This makes arguments of type InputOutputArray required in python unless they
have a default value in C++.

As result following python functions changes signatures in non-trivial way:

* calcOpticalFlowFarneback
* calcOpticalFlowPyrLK
* calibrateCamera
* findContours
* findTransformECC
* floodFill
* kmeans
* PCACompute
* stereoCalibrate

And the following functions become return their modified inputs as a return
value:

* accumulate
* accumulateProduct
* accumulateSquare
* accumulateWeighted
* circle
* completeSymm
* cornerSubPix
* drawChessboardCorners
* drawContours
* drawDataMatrixCodes
* ellipse
* fillConvexPoly
* fillPoly
* filterSpeckles
* grabCut
* insertChannel
* line
* patchNaNs
* polylines
* randn
* randShuffle
* randu
* rectangle
* setIdentity
* updateMotionHistory
* validateDisparity
* watershed

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

changed diagnostic from "warning" to "note" in the python wrapper generator, to suppress some noise in opencv utilities

work on #2100: pyopencv_to functions now can receive argument information through ArgInfo structure. Non-contiguous input numpy arrays are copied. In case of non-contiguous output array the TypeError is thrown.

Added gabor_threads.py sample

adjust the header parser to support "public virtual" construction and make a tweak for multiple inheritance, fix potential memory problem with Python's IplImage.tostring() method (ticket #1486)

partially wrapped features2d framework
added feature_homography.py sample

fixed "import cv" in the new python samples. corrected Python bindings to match the documentation and vice versa (NOTE: in cv2.stereoCalibrate the parameter ordering has been changed)

upgraded to FLANN 1.6. Added miniflann interface, which is now used in the rest of OpenCV. Added Python bindings for FLANN.

make type registration ordering in cv2.so consistent with the declaration order (fixes the class hierarchy; see ticket #1113)

- static class member modifier processing is fixed (moved from 'rettype' to 'func_modlist')

moved Python bindings source code into src subdirectory; preparing to add python/doc and python/test subdirectories