Improve pretzel connector
Improve pretzel connector

Add support for the full player.

Closes #2606.

david-sabata/web-scrobbler,david-sabata/web-scrobbler,fakelbst/Chrome-Last.fm-Scrobbler,inverse/web-scrobbler,inverse/web-scrobbler,fakelbst/Chrome-Last.fm-Scrobbler,carpet-berlin/web-scrobbler,carpet-berlin/web-scrobbler