Feature: Gapless playback for mp3

[bbsixzz]

Please implement gapless playback for mp3.

[NattyNarwhal]

Implementation wise, I think the easiest way to do this is use AVQueuePlayer instead of AVPlayer. We have our own playlist management, but we could probably just build its queue from that.

[f0ff886f]

It looks like according to https://stackoverflow.com/questions/10285545/gapless-playback-with-avqueueplayer-avplayer-is-it-possible, it may not be that simple :(

There is a fork of the mentioned StreamingKit that may help: https://github.com/GlobalRadio/StreamingKit but I think that is a large playback.

The SO question mentions that AVQueuePlayer has a small gap, but it is much better. Maybe that is enough to make thing sound better (as today there is quite a large gap).