emplace already calls std::pair. No need for it again.

No need to emplace when calling std::make_shared.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Found with readability-use-anyofallof
Signed-off-by: Rosen Penev <rosenp@gmail.com>

See commit dfc67c45

Snapcast's protocol documentation is wrong, see
https://github.com/badaix/snapcast/pull/811

New experimental code, first draft - it works, but there's a lot left
to do.  Just look at all the TODO comments.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/975