- do not store user-controlled "FileStorage" pointer
- store FileStorage::Impl pointer instead

* fixed issue #17412

* Update test_io.cpp

GAPI: Migration to IE Core API

* Migration to IE Core API
 - both versions are maintained
 - checked building with all the OpenVINO versions (2019.R1, R2, R3, 2020.4 (newest))

* commit to awake builders

* Addressing comments
 - migrated to Core API in 'gapi_ie_infer_test.cpp'
 - made Core a singleton object
 - dropped redundant steps

* Addressing comments
 - modified Mutex locking

* Update

* Addressing comments
 - remove getInitMutex()
 - reduce amount of #ifdef by abstracting into functions

* return to single IE::Core

* Divide functions readNet and loadNet to avoid warnings on GCC

* Fix deprecated code warnings

* Fix deprecated code warnings on CMake level

* Functions wrapped
 - All the functions depended on IE version wrapped into a cv::gapi::ie::wrap namesapace
 - All this contained to a new "giebackend/gieapi.hpp" header
 - The header shared with G-API infer tests to avoid code duplications

* Addressing comments
 - Renamed `gieapi.hpp` -> `giewrapper.hpp`, `cv::gapi::ie::wrap` -> `cv::gimpl::ie::wrap`
 - Created new `giewrapper.cpp` source file to avoid potential "multiple definition" problems
 - removed unnecessary step SetLayout() in tests

* Enabling two NN infer teest

* Two-NN infer test change for CI
 - deleted additional network
 - inference of two identical NN used instead

* Fix CI fileNotFound

* Disable MYRIAD test not to fail Custom CI runs

original commit: 2813aa7e

Documentation fixes/improvements

* Documentation fixes/improvements

* Remove HASH_UTILS defines

[G-API] Allow building graphs with a dynamic number of inputs and outputs

* Add dinamic graph feature and tests

* Remove unnecessary file

* Review response

* Add implementation of operator += for GRunArgs
And test for that case

* Tests refactoring

* Add doxygen
Review response

* Fix docs

* A small documentation fix

* Review response

* Add tests for more entities

* Add typed tests

* Another typed tests

* Doc fix

* Documentation fix

* Build fix

* Commit for rebuild

* The last one

* G-API: Introduce a new gapi::infer2 overload + gaze estimation sample

* G-API/infer2: Introduced static type checking for infer2

- Also added extra tests on the type check routine

* G-API/infer2: Addressed self-review comments in the sample app

- Also fix build on Linux;

* G-API/infer2: Remove incorrect SetLayout(HWC) + dead code

- Also fixed comments in the backend

* G-API/infer2: Continue with self-review

- Fix warnings/compile errors in gaze estimation
- Dropped the use of RTTI (VectorRef::holds()) from the giebackend
- Replaced it with a trait-based enums for GArray<T> and std::vector<T>
- The enums and traits are temporary and need to be unified with
  the S11N when it comes

* G-API/infer2: Final self-review items

- Refactored ROIList test to cover 70% for infer<> and infer2<>;
- Fixed the model data discovery routine to be compatible with new
  OpenVINO;
- Hopefully fixed the final issues (warnings) with the sample.

* G-API/infer2: address review problems

- Fixed typo in comments;
- Fixed public (Doxygen) comment on GArray<GMat> input case for infer2;
- Made model lookup more flexible to allow new & old OMZ dir layouts.

* G-API/infer2: Change the model paths again

* G-API/infer2: Change the lookup path for test data

* G-API/infer2: use randu instead of imread. CI war is over

G-API args serialization

* args serialization

* GRunArgP draft

* UMat added

* bind added

* DmitryM's review addressed. Code clean up required.

* fix android build

* bind test added

* more comments addressed

* try to fix Mac build

* clean up

* header-based generic implementation (GRunArg)

* clang again

* one more attempt for clang

* more clean up

* More Dmitry's comments addressed.

* monostate removed

* Top level functions and some other comments addressed.

* fix warnings

* disable warning

Pev binary kmeans

* Ongoing work transposing kmeans clustering method for bitfields: the computeClustering method

Ongoing work transposing kmeans clustering method for bitfields: interface computeBitfieldClustering

Fix genericity of computeNodeStatistics

Ongoing work transposing kmeans clustering method for bitfields: adapt computeNodeStatistics()

Ongoing work transposing kmeans clustering method for bitfields: adapt findNN() method

Ongoing work transposing kmeans clustering method for bitfields: allow kmeans with Hamming distance

Ongoing work transposing kmeans clustering method for bitfields: adapt distances code

Ongoing work transposing kmeans clustering method for bitfields: adapt load/save code

Ongoing work transposing kmeans clustering method for bitfields: adapt kmeans hierarchicalClustring()

PivotType -> CentersType Renaming

Fix type casting for ARM SIMD implementation of Hamming

Fix warnings with Win32 compilation

Fix warnings with Win64 compilation

Fix wrong parenthesis position on rounding

* Ensure proper rounding when CentersType is integral

3.4 Allow first capture to return false

* fix first capture timeout

* fix first capture timeout