Add YouTube Video Progress
Add progress bars (or dots) at bottom of YouTube video and progress text on the video page. On the progress text, the current video quality will have a "+" suffix if there's a higher one available. Hovering the mouse cursor onto the video quality text will show the current and available video quality IDs and short description. A "[C]" text will also be shown to indicate that subtitle(s) are available, and hovering the mouse over it will show the available subtitle languages.