The Video class is now available as a separate Composer package (rudloff/alltube-library)
The release package and Docker image now contain only production dependencies
youtube-dl is now a production dependency
Composer does not install ffmpeg or phantomjs anymore
The "avconv" and "avconvVerbosity" options are now respectively "ffmpeg" and "ffmpegVerbosity"

Other fixes:

Setting the "stream" option to "ask" now works correctly
New locales are automatically detected
New Italian translation (thanks to @holoitsme)
If the "best" format does not exist, it will fall back to "bestvideo"
Composer 2 compatibility