Last.fm integration

[rrrnld]

I think it makes sense to handle scrobbling completely on the clientside. I created a branch feature/lastfm to track progress on this. The lastfm API is a a bit ugly but it should work. The main reason is that server-side development takes some time and the new rest API will have to be planned carefully.

It still makes sense to leave some logic related to artist information etc. on the server. The good news is that you don't need any authorization for that (see album.getInfo, artist.getInfo and artist.getSimilar). It should be easier to do this scrobbling on the client though, so maybe we can fix airsonic/airsonic#776 and finally close quite a popular issue.

[rrrnld]

While we're at it, might as well add support for libre.fm. Seems to support the old scrobbling API: https://git.gnu.io/foocorp/librefm/wikis/Librefm_API

[jvoisin]

Please make this easy to disable ♥

[rrrnld]

It would be opt-in, because you need to login to receive a token to submit any kind of scrobble.

[ronilaukkarinen]

+1 for this! I'd help, if I knew more about Clojure.

[ronilaukkarinen]

Not sure if this would help: clojure-lastfm.