4.x
Merge pull request #16150 from alalek:cmake_avoid_deprecated_link_private
updating python tutorials + providing necessary data
update cpp samples and tutorials
samples: use findFile() in T-API samples
Merge pull request #13084 from vpisarev:shuffle_optflow_algos
Merge remote-tracking branch 'upstream/3.4' into merge-3.4
Add namespace specifier for format()
Merge pull request #19755 from mikhail-nikolskiy:ffmpeg-umat