The GLIB_CHECK_VERSION() macro was used improperly, which broke build
on GLib < 2.14.  Add a "!" for negation.

On some systems, the macro IN6_IS_ADDR_V4MAPPED() is not available.
Don't try to convert IPv6 to their IPV4 equivalents in this case.

Add 'Streaming Support section to the configure display, clarify
the text and unify with the rest of the display.

The configure problem was:
./configure: line 6934: ,: command not found

Turn the music_pipe into a simple music_chunk queue.  The music_chunk
allocation code is moved to music_buffer, and is now managed with a
linked list instead of a ring buffer.  Two separate music_pipe objects
are used by the decoder for the "current" and the "next" song, which
greatly simplifies the cross-fading code.

Added music_pipe_allocate(), music_pipe_push() and
music_pipe_cancel().  Those functions allow the caller (decoder thread
in this case) to do its own chunk management.  The functions
music_pipe_flush() and music_pipe_tag() can now be removed.

The queue update after a seek was wrong: the queued song is cleared by
a successful seek.  This caused queue/cross-fading problems after a
seek.

After the decoder command was obtained, don't wait until libflac
detects EOF (as a side effect), quit the decoder immediately.  This
check was missing completely.

When the MPD core sends the decoder a command while
flac_process_single() is executed, this function fails.  Abort the
decoder only if not seeking.  This fixes a seeking bug.

Moved some code from music_pipe_write() and music_pipe_expand().  Only
music_chunk.c should access the music_chunk internals.

Log the real period and buffer size.  This might be useful when
debugging xruns.  Note that the same information is available in
/proc/asound/card*/pcm*p/sub*/hw_params

Since there are no other callers than stdout, this wouldn't be a
problem, but since there maybe in the future go ahead and fix it.

function was implemented in the version we are comparing to so there must be higher or equal

There are a few high-end devices (e.g. ICE1724) which cannot even play
16 bit audio.  Try the 32 bit fallback, which we already implemented
for 24 bit.

[mk: merged memory leak patch; fixed indentation (tabs); fixed
documentation typo]

The lastfm input plugin enables MPD to play lastfm:// URLs.  This
plugin is not complete yet: it plays only the first song in the
last.fm playlist, and the playlist parser isn't even implemented
properly.

Keep valgrind happy.

Allow input plugins to configure with an "input" block in mpd.conf.
Also allow the user to disable a plugin completely.

Instead of hard-coding the plugin global initialization in
input_stream_global_init(), make it walk the plugin list and
initialize all plugins.

Create a sub directory for input plugins.

Start to separate private from public input_stream API.

[mk: cast off_t to uint32_t; same fix for aiff.c]

Added a small AIFF parser library, code copied from the RIFF parser
(big-endian integers).  Look for an "ID3" chunk, and let libid3tag
parse it.

Added a small RIFF parser library.  Look for an "id3" chunk, and let
libid3tag parse it.

Some sound chips/drivers (e.g. Intel HDA) don't support 24 bit
samples, they want to get 32 bit instead.  Now that MPD's PCM library
supports 32 bit, add a 32 bit fallback when 24 bit is not supported.