* fixed OpenCL functions on Mac, so that the tests pass

* fixed compile warnings; temporarily disabled OCL branch of TV L1 optical flow on mac

* fixed other few warnings on macos

Input arrays must be depth CV_8U and of identical size.

This adds the possibility to use multi-channel masks for the functions
cv::mean, cv::meanStdDev and the method Mat::setTo. The tests have now a
probability to use multi-channel masks for operations that support them.
This also includes Mat::copyTo, which supported multi-channel masks
before, but there was no test confirming this.

- 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;

NaN values handling issue

https://sourceforge.net/p/predef/wiki/OperatingSystems

- remove unused code
- added: #if CV_ENABLE_UNROLLED in Hamming's functions

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

 - make sure SIMD optimization works even when AVX is not available

 - add v_popcount in universal intrinsic
 - add test for v_popcount
 - add wrapper of popcount for both MSVC and GCC

--perf_instrument parameter now has int type and 0, 1, 2 modes (1 - simple trees, 2 - expanded trees for functions with same name but different calling address);

Maximum depth limit var was added to the instrumentation structure;

Trace names output console output fix: improper tree formatting could happen;
Output in case of error was added;

Custom regions improvements;

Improved timing and weight calculation for parallel regions; New TC (threads counter) value to indicate how many different threads accessed particular node;

parallel_for, warnings fixes and ReturnAddress code from Alexander Alekhin;

* normHamming done with AVX 2 intrinsics.

* fixed compiling AVX2-optimized norm hamming with MSVC

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