This fixes a regression in the patch "return multiple tag values per
song": even when the song has values for the specified tag type, the
empty string gets added to the set, because the "return" was removed.
This patch adds a flag which remembers whether at least one value was
found.

This has been reimplemented in the "rewind" input plugin.

This replaces the rewinding buffer code from the CURL input plugin.
It is more generic, and allows rewinding even when the server sends
Icy-Metadata (which would have been too difficult to implement within
the CURL plugin).

This is a rather complex patch for the stable branch (v0.15.x), but it
fixes a serious problem: the "vorbis" decoder plugin was unable to
play streams with Icy-Metadata, because it couldn't rewind the stream
after detecting the codec (Vorbis vs. FLAC).

Support deprecated MIME types such as "audio/x-ogg".  Support new
types such as "audio/flac".

When collecting tag values for the result set, add all of a song's tag
values of the searched type.  This affects the "list" command.
Previously, "list" only considered the first tag value of a song.

Don't clear the music pipe when seeking has failed - check the
"seeking" flag instead of "command==SEEK".  Clear the "seeking" flag
in decoder_seek_error().

First multiply the floating point return value of
decoder_seek_where(), then cast to integer.

Free the "context" pointer in the method archive_plugin.close().

Fixes a memory leak: the "archive" input plugin opens the archive, but
never closes it.  This patch moves the responsibility for doing that
to archive_plugin.open_stream().  This is an slight internal API
change, but it is the simplest and least intrusive fix for the memory
leak.

g_free(NULL) is allowed.

Fixed memory leak in error handler.

This enables valgrind debugging after an error occurred.

Enable archive plugin debugging.

This code has never made any sense, and has broken some of the archive
plugin.

Use the signed C99 type int8_t instead.

Mixers with the "global" flag set aren't closed automatically when the
output device is closed.  Thus, they might still be open when MPD
shuts down.

This fixes an inconsistency in the stored playlist subsystem: when
obtaining the list of playlists (listplaylist, listplaylistinfo), the
file names in the playlist directory are converted to UTF-8 (according
to filesystem_charset), but when saving or loading playlists, the
filesystem_charset setting was ignored.

Call spl_valid_name() in spl_delete().

Don't allocate the file name before the playlist_dir==NULL check.

If we define id3v1_encoding, then the tags are not added to the
database.

The plugin code tried to force libavcodec to supply stereo samples.
That however has never actually worked.  By removing this code, we are
able to play surround files for the first time.

Removed the "vtrack" local variable (which triggered a gcc warning
because it was after the newly introduced NULL check), and run
strtol() on the original parameter.

The function flac_vtrack_tnum() was missing a strrchr()==NULL check.

Allow RIFF/AIFF ID3 tags up to 4 MB (old limit was 256 kB).  This
might still be too small for some users, and when somebody complains,
we might do something more clever (like streaming the data into
libid3tag?).

On some platforms, libavcodec wants the output buffer aligned to 16
bytes (because it uses SSE/Altivec internally).  It will segfault when
you don't obey this rule.

If flac_container_decode() gets a seek destination which is out of
range, it ignores the SEEK command (never finishes it).  This leads to
MPD lockup, because the player thread waits for completion.

The oggflac plugin has been completely broken for quite a while and
nobody has noticed - maybe we should remove it?

We need the function zzip_file_stat().

We're using API functions which are not available in 0.3.

This function was not present in SQLite < 3.4.

Should be "lastfm_user", not "lastfm_username".

The line buffer had a fixed size of 5 kB, and was allocated on the
stack.  This was too small for some users.  As a hotfix, we're
increasing the buffer size to 32 kB now, allocated on the heap.  In
MPD 0.16, we'll switch to dynamic allocation.

Convert the metadata with the libavformat function av_metadata_conv().
This ensures that canonical tag names are provided by libavformat, and
we can remove the "artist" vs "author" workaround.

When you disable the "follow_outside_symlinks" or the
"follow_inside_symlinks" setting, the next update should remove the
now-ignored files from the database.