* Updated ICV packages and IPP integration

* core(test): minMaxIdx IPP regression test

* core(ipp): workaround minMaxIdx problem

* core(ipp): workaround meanStdDev() CV_32FC3 buffer overrun

* Returned semicolon after CV_INSTRUMENT_REGION_IPP()

- IPHONEOS_DEPLOYMENT_TARGET=8.0 by default (minimal for XCode 10)

* Document distance functors in dist.h

* Add spec for Distance

* Generate appropriate links for symbols

Relevant guards can be found in
https://github.com/opencv/opencv/blob/ef5579dc8667e5eb5e149acc4af898421eed99da/modules/features2d/src/kaze/AKAZEConfig.h#L8
and
https://github.com/opencv/opencv/blob/ef5579dc8667e5eb5e149acc4af898421eed99da/modules/ml/include/opencv2/ml.hpp#L44

Exceptions caught by value incur needless cost in C++, most of them can
be caught by const-reference, especially as nearly none are actually
used. This could allow compiler generate a slightly more efficient code.

- This is to accommodate the variabiilty in floating-point operations in new platforms/compilers
- Specifically due to the error margin found in NVIDIA Jetson TX2

- drop unnecessary matrix initialization

* js: update build script

- support emscipten 1.38.12 (wasm is ON by default)
- verbose build messages

* js: use builtin Math functions

* js: disable tracing code completelly

  * remove race condition
  * upload _prevPts to OpenCL device explicitly before calling "sparse"