Added a new optional parameter for the shout plugin called "url".

I wanted mpd to play a mp3 stream from a music website.  The stream is
only available to subscribers, which restriction is enforced through
normal http authentication.  However, the URL I get from the website
is not the final URL of the stream, but a generic URL which points to
the real one through a redirect (code 301).  Thus, I cannot predict
the final URL, and so I cannot use the username:password hack to force
the authentication, and mpd (libcurl on mpds behalf) fails to grab the
stream.

libcurl allows the option CURLOPT_NETRC to be set and then the
credentials can be stored in the good old .netrc file (in this case it
would be ~mpd/.netrc, of course).  But mpd doesn't set this option.  I
think it should.

Remote Audio Output Protocol (RAOP), for Apple devices.

Don't finish the current command twice.

This bug was never noticed, but was revealed by a new assertion check.

Merge some code.

GMutex/GCond guarantee that the access to removed_song is protected.

Remove the decoder dependency on player_control.  All player_control
was needed for is to signal the player thread, and we can do that with
a simple GCond as well.

Only dc_command_wait_locked() is really being used.

dc_new() allocates the object and returns it.  dc_free() frees it
(replaces dc_deinit()).

Allocate a player_control object where needed, and pass it around.
Each "client" object is associated with a "player_control" instance.

This prepares multi-player support.

In findAddInDirectory(), call playlist_append_song() directly, to have
some more type checking.

Conflicts:
	NEWS

A bit of automake magic (see info automake "Per-Object Flags").
Compile-tested.

Seems like we forgot to give this module a name...  this can crash MPD
on startup.

Conflicts:
	NEWS
	configure.ac

Conflicts:
	NEWS
	configure.ac
	src/directory.h

When a music_chunk to be crossfaded consists only of a tag,
cross-fading is not possible, and led to an assertion failure.  This
patch just discards those, as if cross-fading was not enabled.

During the whole output thread, the audio_output object is locked, and
it is only unlocked while waiting for the GCond and while running a
plugin method.  The error handler in ao_play_chunk() attempted to lock
the object again, which was code from MPD 0.15.x which should have
been removed a long time ago.

Until the decoder plugin has called decoder_initialized(), the player
may not submit seek commands.  This however could occur with a slow
decoder and a CUE file with a virtual song offset.  This patch adds
another check.

When you don't explicitly set an output sample rate, liblame tries to
guess an output sample rate from the input sample rate.  You would
think that this "guessing" consists of just setting both equal, but
that is not the case.  For 44.1kHz at 96kbit/s, liblame chooses
32kHz.  This patch explicitly configures the output sample rate, to
stop the bad guessing.

This is a MPD 0.16 regression: when playing a 24 bit file, the switch
to 16 bit was made only partially, after mBytesPerPacket and
mBytesPerFrame had already been applied.

That means mBytesPerFrame referred to 24 bit, and mBitsPerChannel
referred to 16 bits.  Of course, that cannot work.

Use "printf" instead.