Add retrieve encoded frame to VideoCapture

* Add capacity to retrieve the encoded frame from a VideoCapture object.

* Correct raw codec and pixle format output from ffmpeg capture.

* Remove warnings from build.

* Added VideoCaptureRaw subclass.

* Include abstract base class VideoCaptureBase and rename new subclass VideoContainer as suggested by mshabunin.

* Remove using.

* Change base class name for compatibility with jave bindings generator.

* Move grab and retrieve and add override specifier

* Add setRaw and readRaw to IVideoCapture interface
-setRaw to disable video decoding and enable bitstream filters from mp4 to h254 and h265.
-readRaw to return the raw undecoded/filtered bitstream.
Add createRawCapture to initiate a backend with setRaw enabled.
Remove inheritance and use an independant VideoContainer subclass with IVideoCapture member.

* Address unused parameter warings.
Remove VideoContainer from python bindings as it no longer returns a Mat.
Use opencv type uchar instead of unsigned char.
Add missing destructor to VideoContainer class.

* Address build warnings and include all params in documentation.

* Include deprecated bitstream filtering API.

* Update codec_id query to work with older ffmpeg api's.
Change api version defines to be consistent - most recent api version first.

* Fix typo.

* Update test to work with naming of new files in the extra repo

* Investigate test failure

* Check bytes read by ffmpeg

* Removed mp4 video container test

* Applied suggested changes.

* videoio: rework API for extraction of RAW video streams

- FFmpeg only

* address review comments

Introducing the sample of Face Beautification algorithm implemented via Graph-API

* Introducing the sample of Face Beautification algorithm implemented via Graph-API
- 'gapi/samples/face_beautification.cpp' added
- FIXME added in 'gcpukernel.hpp'

* INF_ENGINE fix
- preprocessing clauses added not to run the sample without Inference Engine

* INF_ENGINE fix 2
- warnings removed

* Fixes
- checking IE version cut as there is no dependency
- some alignments fixed
- the comment about preprocessing commands fixed

* ie::backend() issue fix (according to dmatveev)
- as the sample needs the cv::gapi::ie::backend() to be defined regardless of having IE or not, there is its throw-error definition in `giebackend.cpp` now (by dmatveev)
- for the same reason, #includes in `giebackend.hpp` are fixed
- HAVE_INF_ENGINE check is removed from the sample

* imgproc: fix bit-exact GaussianBlur() / sepFilter2D()

- avoid kernels with bad approximation
- GaussiabBlur - apply error-diffusion approximation for kernel (8-bit fraction)

* java(test): update features2d ref data

* test: update test_facedetect

Js test puppeteer

* run_puppeteer.js / tests

* js run test section

* rollback html

* whitespace

* js: update OpenCV.js tests infrastructure

* js: exclude puppeteer from default 'npm install'

* js: update notes

* js: more fixes in run_puppeteer

* fix build folder

Implement Camera Multiplexing API

* IdideoCapture + two wrong function

function waitAny

Add errors catcher

Stub for Python added.

Sifting warnings

One test added

Two tests for camera and Perf tests added

* Perf sync and async tests for waitAny() added, waitAnyInterior() deleted, getDeviceHandle() deleted

* Variable OPENCV_TEST_CAMERA_LIST added

* Without fps set

* ASSERT_FAILED for environment variable

* Perf tests is DISABLED_

* --Trailing whitespace

* Return false from cap.cpp deleted

* Two functions deleted from interface, +range for, +environment variable in test_camera

* Space deleted

* printf deleted, perror added

* CV_WRAP deleted, cv2 cleared from stubs

* -- space

* default timeout added

* @param changed

* place of waitAny changed

* --whitespace

* ++function description

* function description changed

* revert unused changes

* videoio: rework API for VideoCapture::waitAny()

- Extended NV12 support in Fluid Core engine to cover I420

JS - adds a tutorial about running opencv.js in Node.js

Implement GArik's comments

Remove unnecessary c_str()

Fix brace position

Supported ONNX Squeeze, ReduceL2 and Eltwise::DIV

* Support eltwise div

* Fix test

* OpenCL support added

* refactoring

* fix code style

* Only squeeze with axes supported

Fix an error during Windows installation caused by trying to create the already existing Build directory. Also excluding intermediate steps for Install directory creation.