ALSA is just one out of many output plugins, and detailed plugin
documentation should only live in the user manual, without having
duplicates in the (brief) manpage.

Also move "mixer_type" to the "optional audio output parameters"
section; it is a generic option, not specific to ALSA.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/552

expand %h to the system hostname and default to a zeroconf string that
contains %h

Remove another dependency on the config/Global library.

Moving some text from the manpage.  Oh, documentation is still a mess.

A complete list which replaces the incomplete list in the mpd.conf
manpage.

MPD does not really take advantage of memory-mapped I/O by generating
data right into the ALSA buffer; using plain snd_pcm_mmap_writei() has
no advantage compared to snd_pcm_writei().  Let's kill this
non-feature.

Drop support for misencoded tags.  People should not be using ID3v1
anyway.

The Release Track Id uniquely identifies a recording on a release - that
is, even if a recording appears twice on a release (meaning that the
combination of recording and release id are not enough to figure out
which one it is), the release track id will allow differentiating the two.

The tag names are taken from
https://musicbrainz.org/doc/MusicBrainz_Picard/Tags/Mapping

The real and detailed documentation is in the user manual.

Move from doc/mpd.conf.5.

Move from doc/mpd.conf.5.

2 MB was too small for cross-fading a 24 bit file.  Increasing to 4 MB
is still not too large for weak machines, but is enough for
cross-fading.

Look for "$XDG_CONFIG_HOME/mpd/mpd.conf", similar to where mpd looks
for the file under Windows.

mpd.conf.5 lists follow_outside_symlinks and follow_inside_symlinks
under REQUIRED, yet also documents a default value for these options,
which only makes sense if they're not actually required.

Additionally, update mpdconf.example to refer to mpd.conf(5) for the
complete list of tags instead of trying to repeat it.

Allow port specification in "bind_to_address" settings.

When set, MPD will not auto-start playback on startup; it will be in
"paused" state.

Added a new optional parameter for the shout plugin called "url".

Limits the depth of the watched directories.  This is useful to keep
resource usage down and speed up MPD startup.

Add an option for each audio output which enables the use of the
hardware mixer, instead of the software volume code.

This is hardware specific, and assumes linear volume control.  This is
not the case for hardware mixers which were tested, making this patch
somewhat useless, but we will use it to experiment with the settings,
to find a good solution.

Instead of using MPD's audio output name (setting "name"), use a
separate configuration option.  Change the default to "Music Player
Daemon".