Issue 8647: Updated doc for cv::matchTemplate to reflect current support for methods when mast template is supplied.

Spell correction

Corrected the spelling which was used in explanation for parameters.

from linked targets of base modules

This updates the public headers to use _Nm instead of _N in templates
since _N is defined by the widely used ctype.h.

- persistence.cpp code expects special sizeof value for passed structures
- this assumption is lead to memory corruption problems
- fixed/workarounded test to prevent memory corruption on Linux 32-bit systems

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

Updated comments for cv::ellipse and cv::ellipse2Poly to clarify some behaviour that has confused some users.

Amend: Delete trailing whitespace to make doc tests happy

https://www.mathjax.org/cdn-shutting-down/#alternative-cdn-providers