backport commit 13f76375

backport commit 8c092493

Fix cudacodec::VideoReader::nextFrame python bindings

* Signla to python bindings generator that nextFrame's OutputArray is a GpuMat.
Also remove duplicate test in cudacodec

* cudacodec: drop CV_GPU, wrap GpuMat only

* Make it explicit that frame in nextFrame is GpuMat and cannot be multiple types as implied by OutputArray

VLA is part of C99, but still not part of C++ standard
Replace float variable-length-arrays with unique_ptr arrays (which are
part of C++14)

not needed since we require OGRE 1.11.5 via CMake

Added constructors and destructors for RgbdPlane

* declared constructors and destructors of RgbdPlane

* definitions written

* tests for python bindings added

OpenCV fix 14774 breaks cudacodec

* Example to describe comilation issue

* Added required changes, builds with -DWITH_FFMPEG=ON|OFF

* Working with standard ffmpeg cap.

* Changed cudacodec to use new retrieveRaw() function, to retrieve the raw encoded bitstream, from the videoio module  instead of its own implementation.

* Fix cv::cudacodec::VideoWriter

* Update to use VideoContainer

* Remove header used in testing

* Remove warning

* remove dependence on redundant ffmpeg codecs

* cudacodec: use .set(CAP_PROP_FORMAT, -1) to extract RAW streams

* whitespace

* addressed alalek's comment