there are some places in the mpd-0.17.4 sources where a "false" is
used instead of a NULL pointer.

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.

Fixes valgrind warning.

Eliminates one IDLE_PLAYER call in playlist_control, and add two new
ones to player_thread.  Fixes Mantis bug 3636.

Check audio_format_defined().

AVFrame must be allocated with avcodec_alloc_frame().

If END is omitted, mpd should use the highest possible value instead of raising an error.
This partially reverts 52e9cab1

When all outputs fail, MPD automatically pauses playback, but did not
emit the IDLE_PLAYER event.  Thus, clients were not woken up.  (Mantis
3665)

This file is generated during configuration and should be ignored.

- Add mandatory "name" setting for winmm/openal examples.

- Fix the language in openal sample (a -> an)

- Added replaygain_missing_preamp and replaygain_limit settings

- Added information about "auto" replay gain mode

At least in my configuration libgme lacks .pc file
thus could not be detected with pkg-config.

Track whether _finish() has been called, and deliver all partial
results then.  Fixes Mantis ticket 0003621.

Rationale: vanilla libid3tag does not have any pkg-config stuff
and fails to detect because symbols from libz are not found.

- fix potential memory leak of system_path

  'Potential' because currently g_get_system_config_dirs()
  returns single entry on Windows, but that might change.

- remove incorrect g_free() call

  It's not required at all because
  g_get_system_config_dirs() returns GLib owned memory.

- remove extra semicolon

Since some configurations use the "bind_to_address" option in their
/etc/mpd.conf, the systemd service file must wait for the
network.target or else mpd will start before it and thus fail due to
no iface.

The song's URI must be UTF-8, not filesystem character set.

Fixes minor Windows compatibility problem.

Implements Mantis feature request 3582.