[vsync] ensure we don't set or show VSYNC_DRIVER on those systems that don't support it. Only show or set on Linux and FreeBSD.
[vsync] switch default in settings.xml to something supported on all systems (ALWAYS) and quirk it on Linux and FreeBSD
Neptune Add audio/x-flac MIME type

Change streaming FLAC MIME type from application/octet to audio/x-flac to
support Frontier Silicon systems (such as the Axis X3) that require
this. (Others don't care.)

FLAC not added to DefaultDlnaMap as * suffices.

(Commit amend: tabs --> spaces)
(Commit amend: flac --> x-flac)
Merge pull request #4479 from mossywell/master

Change FLAC MIME type
[airtunes] - don't handle "OnStop" (restore volume) in AirTunesServer - its already handled in AirPlayServer
[videodb] fix crash linking a movie to a show if there's no tvshows left to link.
[videodb] show select dialog for linking a movie to a show, even if there's only one show to link to.
Merge pull request #4463 from jmarshallnz/osx_vsync_always

[osx] vsync should default to always
[airplay] - don' restore the volume when picture airplay is beeing stopped
paplayer: use position based seeks for ffmpeg demuxer
WASAPI: add 192khz sample rate in case we added HD formats
Merge pull request #4493 from Memphiz/airplaypicvolume

[airplay] - fix unwanted volume restore
Merge pull request #4488 from FernetMenta/paplayer

paplayer: use position based seeks for ffmpeg demuxer
Merge pull request #4495 from FernetMenta/aefixes

WASAPI: add 192khz sample rate in case we added HD formats