- Optimizations set change. Now IPP integrations will provide code for SSE42, AVX2 and AVX512 (SKX) CPUs only. For HW below SSE42 IPP code is disabled.
- Performance regressions fixes for IPP code paths;
- cv::boxFilter integration improvement;
- cv::filter2D integration improvement;

Updated integrations for:
cv::split
cv::merge
cv::insertChannel
cv::extractChannel
cv::Mat::convertTo - now with scaled conversions support
cv::LUT - disabled due to performance issues
Mat::copyTo
Mat::setTo
cv::flip
cv::copyMakeBorder - currently disabled
cv::polarToCart
cv::pow - ipp pow function was removed due to performance issues
cv::hal::magnitude32f/64f - disabled for <= SSE42, poor performance
cv::countNonZero
cv::minMaxIdx
cv::norm
cv::canny - new integration. Disabled for threaded;
cv::cornerHarris
cv::boxFilter
cv::bilateralFilter
cv::integral

HAVE_IPP_ICV_ONLY will be undefined if OpenCV was linked against ICV packet from IPP9 or greater. ICV9+ packets will be aligned with IPP in OpenCV APIs
This will ease code management between IPP and ICV

IPP can be switched on and off on runtime;

Optional implementation collector was added (switched off by default in CMake). Gathers data of implementation used in functions and report this info through performance TS;

TS modifications for implementations control;

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

Also move cv::linemod to own header

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

Declare vars as locally as possible

disabled the use of SSE4 instructions as well to make the code compatible with the old Intel and AMD chips

added test for the old cvHaarDetectObjects. disabled AVX optimization in haar.cpp. it should cover tickets #2534, #2591, #2669

#523 Fix the problem where the MaxSize parameter in cvHaarDetectObjects does not work when the flag CV_HAAR_SCALE_IMAGE is not set.