Standardize 'previous' method behaviour

[Toreno96]

In modern media players, de facto standard is that the 'previous' method can change current track to the previous track or start it from the beginning.

What was the rationale behind the workaround to remove the latter functionality?

Alternatively, it could be configurable (in the extension settings page?).

[otommod]

I guess I just didn't like it and the players I use don't do it like that. It could be made an option but that would mean adding an settings page and the like... feel free to open a PR for that if you want!!