whitespace fix

fixed find_obj.py

keep old const names for compatibility

maintain set of visited namespaces in CppHeaderParser
WARNING: REMOVED const name conversion (SomeConstName -> SOME_CONST_NAME), discussion needed

submodule method tables generation

gen2.py reports headers it processes
cmake file restructured

 - all parsed headers are included into "cv2.cpp" with "pyopencv_generated_include.h"
 - types starting with "Ptr_" converted to "Ptr<...>" form (avoids many typedefs in "cv2.cpp")

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* Remove outdated overloads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.