OpenCV 3.4.4

OpenCV 3.4.4

* samples: rename starter_imagelist.cpp

* samples: rename intelperc_capture.cpp => videocapture_intelperc.cpp

* samples: rename openni_capture.cpp => videocapture_openni.cpp

* samples: rename image_sequence.cpp => videocapture_image_sequence.cpp

* samples: rename gstreamer_pipeline.cpp => videocapture_gstreamer_pipeline.cpp

* samples: rename autofocus.cpp => videocapture_gphoto2_autofocus.cpp

* samples: rename live_detect_qrcode.cpp => qrcode.cpp

G-API: Doxygen class reference

* G-API Doxygen documentation: covered cv::GComputation

* G-API Doxygen documentation: added sections on compile arguments

* G-API Doxygen documentation: restructuring & more text

* Added new sections (organized API reference into it);
* Documented GCompiled, compile args, backends, etc.

* G-API Doxygen documentation: documented GKernelPackage and added group for meta

* Add support for ConvTranspose when parsing ONNX.

* Add support for ConvTranspose when parsing ONNX.

* Add test for Deconvolution

broken in 11eafca3

  - update parameter in carotene

Configures and loads OpenCV bindings extension including 3rdparty dependencies

Based on running Python specify:
- configure PYTHON_PATH (via "sys.path")
- configure LD_LIBRARY_PATH / PATH

- drop EnableDelayedExpansion

- drop EnableDelayedExpansion
- pause on failed commands (non-interactive mode)

The load() function returns a new object, and as such does not use the one it is called on.
This commit updates the uses of model.load in this program so it will work as intended and not throw an error.