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

Requiring this prefix makes the client's intention very clear, but it
was too hard to understand why this prefix was needed.  Initially, my
intention was to differentiate from broken clients which prefix relate
URIs with a slash; once MPD allowed that.  In the past few years
however, MPD has disallowed that, and there was no significant
breakage (except for the "add /" special case which some clients
apparently still do).  So I figure it's about time to define that an
URI that begins with a slash points to an arbitrary file on the file
system.

Mapped to "=" in the MPD protocol.  This is the first operator,
initially supporting value matches in the MPD protocol.

A priority should be a volatile thing: it should schedule a song for
playing back once, but it should not affect the next time the queue
gets played.

Fix incorrect description of the "songs" field and add missing
"albums" field.
Signed-off-by: Joachim Fasting <joachifm@fastmail.fm>

Manipulates the playback range of a queued song.

Lists files and directories.  Supports storage plugins.

Restores the features from the previous draft commands "findin" /
"searchin".

This reverts commit a577944a.

Will be replaced by new options for the old commands "search" and
"find".

This command was removed by commit 206392ad (MPD 0.16), even though it
was been proven useful for some very simple clients.  On request, I
add it to the protocol again.