When we don't have enough data, generate some silence, hoping the
input buffer will fill soon.  Reducing the render buffer size is not
legal.

Blocking inside the render callback is forbidden, and this sleep call
didn't make any sense.

For simpler seeking within current song.

Moving songs using either 'move' or 'moveid' to position -1 (after the
current song) would fail for a song which is just before the current
song.
This patch corrects the check to see if the current song is in the range
to be moved. Since the range is from `start` up to `end` (exclusive) the
check was incorrect, but is now fixed.

This plugin's use of the "Timer" library was wrong; it added the same
amount of virtual data in every iteration in _play(), but did not
actually play something.  This created an artificial, but useless,
delay.  This patch implements the method _cancel(), and implements
hard-coded sleep values.  This is only slightly better, but does not
attempt to look sane.

The implementation of cancel() did not work well: you cannot use
alSourceUnqueueBuffers() to unqueue queued buffers, and our function
openal_unqueue_buffers() left the OpenAL library in a rather undefined
state; nothing was supposed to be queued, but the "filled" variable
was not reset.

The expression "!format" does not make sense, and cannot occur.

Unnecessary overhead.

Conflicts:
	NEWS
	configure.ac

The OpenAL specification says that AL_FORMAT_MONO8 and
AL_FORMAT_STEREO8 expect unsigned 8 bit samples, but MPD uses unsigned
samples.

The local variable was already divided by 1000, and the return value
was being divided by 1000 again - doh!  This caused delays in the
httpd output plugin that were too small by three orders of magnitude,
and the buffer was filled too quickly.

Replace -I with -isystem in GLIB_CFLAGS.

This workaround leads to an infinite loop instead of an assertion
failure, but hey, now it's libmp4ff's fault.

Make valgrind find more buffer misuses.  Buffer contents are not
persistent, they get invalidated by pcm_buffer_get(), because this
function may allocate a new buffer, but will not copy old data.

Silently choosing default is misleading and can cause hours of investigation.
It's better to fail immediately telling user what is wrong with config.

If output plugin fails to init it will try to call ao_base_finish() immediately,
which segfaults because replay gain filters are not initialized yet and contain
garbage values.

It appears the musepack section has not really been reviewed in some
time, many parts unfunctional, others, just unnecessary.

Conflicts:
	Makefile.am
	NEWS
	configure.ac
	src/encoder/flac_encoder.c
	src/log.c
	src/pcm_buffer.c

Initialize the audio_format before calling avcodec_open(), because
avcodec_open() will fill bogus values.

Yet another common support case.

This is a common support case, and hopefully, the new error message
will allow the user to understand the error without requiring support.

Use stat() instead of g_file_test() to detect other types of errors,
such as "permission denied".