OpenCV 4.1.1

OpenCV 3.4.7

* Unroll multiply and add instructions in dotProd_32f - 35% faster.

* Eliminate unnecessary v_reduce_sum instructions.

* G-API: fix GOCLExecutable issue with UMat lifetime

Add tests on initialized/uninitialized outputs for all
backends

* Use proper clean-up procedure for magazine

* Rename InitOut test and reduce tested sizes

* Enable output allocation test

G-API: GAPI_TRANSFORM internal functionality rework (#14952)

* Change internal pattern and substitute signatures and refactor tests

* Enhance GArrayU with type-checker function

Add a couple of new tests on GAPI_TRANSFORM

* Improve support for Windows Embedded Compact

* Remove redundant set(WINCE true) and format CMake

* Added support for the ONNX "ReduceMean" Layer. (as this is the same as the GlobalAveragePool)

* Add ReduceMean test

* Fix ONNX importer

* Fix ReduceMean

* Add assert

* Split test

* Fix split test

 - added ability to use custom implementation of "parallel for" function

  * use SOLVE_EPNP for the initial guess