track removals are broken

[simon-weber]

Google seems to have moved to a new endpoint for removing list entries, 404ing the calls to deletesong.

Here's the new endpoint:
POST https://play.google.com/music/services/deleteplaylisttrack?u=0&format=jsarray&xt...&dv=...&obfid=...'

[["sessionid",1],["playlistid",["entryid"],["songid"]]]

successful response:
[[0,1,1],[]]

I'll get a fix out tonight.