Be portable on WIN32.

Sorts remaining songs by priority.  This can be used for the
much-demanded "queue feature".

Conflicts:
	NEWS
	configure.ac

av_open_input_stream() has been deprecated.

AVMetadata has been deprecated.

For accessing the child of a directory, one needs X_OK on the
directory.

This patch seems a bit ugly, maybe it would be a bit cleaner with gotos.

Was always displayed as "no", even if one was found.

FFmpeg/libav have dropped AVIO_RDONLY in favor of AVIO_FLAG_READ. This
patch fixes that in MPD.

Don't calculate the song duration when the sample rate is 0 (division
by zero crash).

This patch fixes a typo in doc/user about playlist plugins.

Its in the top commit in my repository in a branch called 'doc_fix':
git://github.com/mcfiredrill/mpd.git

Conflicts:
	src/decoder/ffmpeg_decoder_plugin.c

Keep those when scanning for empty directories.  The check in
playlist_vector_is_empty() was missing.

It's a no-op and deprecated.

URLContext is deprecated.

g_path_get_dirname() returns "." when there is no directory name in
the given path.  This patch adds a workaround for that.

avcodec_decode_audio3() has been added in libavformat 52.25.0, and the
predecessor avcodec_decode_audio2() has been deprecated.

fixes build with lavc 53.