Especially in the case that volume-save was set to false...
This adapts to behaviour of the other aout modules.

fixes #8501

Close #8500
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

Close #8498

(request_vout is always non-NULL)

taglib.cpp had a completely ordered priority list of picture types to
use for album art from ID3v2 tags.
Since FLAC uses the same picture type field as ID3v2, use the same
priorities.
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

When multiple pictures are embedded in a file, the FLAC demuxer
prioritizes them based on the picture type.
This ports the same algorithm over so it can be used by Vorbis and Opus.
It also extends its behavior for FLAC to work with both pictures
embedded in VORBIS_COMMENT blocks and in normal PICTURE blocks.

This also plugs a memory leak in vorbis_ParseComment() when parsing
METADATA_BLOCK_PICTURE tags.
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

This makes album art work for formats like Vorbis and Opus which do
 not have metadata available immediately after Open().
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

... to allow toggling between playlist and video view in lion
fullscreen mode.

close #8496

Create the "equalizer-bands" and "equalizer-preamp" variables if not yet
created to ensure that callbacks are added successfully.

Note that this is a hack to work around a lack of proper notification
as to when these variables are created/deleted.

auhal: fix SPDIF -> default device fallback if SPDIF device is unplugged during playback (close #8286)