[feature] Implement sound system auto-detection

[spiralofhope]

From #14 (comment)

The appropriate system (OSS vs ALSA vs Pulse) should be autodetected. Then, if there are multiple soundcards, and multiple volume controls, the right one should be selected again.

[xi]

There is already some kind of autodetection. @andreasvc what would you improve?

[andreasvc]

The current autodetection only tests if the volume can be changed without generating an exception, but this is no guarantee that you get a volume control that effectively changes the playback volume, e.g., because Pulse is installed but not actually used, or because there are multiple sound cards.

Handling all cases seems complex, so maybe doing the volume control through the player makes things easier.