Make the audio_format argument non-const.  Allow the open() method to
modify it, to indicate that it wants a different input audio format
than the one specified.  Check that condition in chain_filter_open(),
and fail.

The pcm_volume library supports 32 bit samples, there's no reason to
disallow it in the filter plugin.

Detect misconfiguration during MPD startup, not when playback begins.

Indicate success and error.

This plugin cannot be configured.

Don't close child filters in the filter() method.

This plugin is the groundwork for MPD's future generic CUE sheet
support.  That's not complete yet, e.g. there is no way for a playlist
plugin to address an arbitrary position within a music file.

When no plugin matches the URI scheme, try the file name suffix.

Use open_uri() / open_stream() only after checking that they are
implemented.

Get duration from track_get_length().

Merge code from cue_tag_file() and cue_tag_string().

It's illegal to pass NULL here.  This should not be ignored silently.

Removed the NULL check.

This fixes a NULL pointer dereference in case of archive plugin
failure.

Make archive_file a "real" struct, extended by all plugins.  Add the
plugin pointer to it.  Wrap all method calls in functions.

Moved the archive plugin "extern" declarations into each plugin
header.

Use the raw struct name instead.

Based on libiso9660.

Use g_path_get_basename() instead of manually filtering the path
name.  Big advantage: g_path_get_basename() cannot fail.

For the fluidsynth plugin.

This fixes a regression: a boolean value was returned from
decoder_input_buffer(), but the caller chose to do a "<= 0"
comparison.

.. instead of manually checking pathname[0]=='/'.
g_path_is_absolute() is portable.

Don't attempt to fill the whole buffer in the read() method, return
whatever libbz2 provides with the first successful BZ2_bzDecompress().

Use the raw struct name.

This plugin is based on libzzip.

Conflicts:
	src/archive/bz2_plugin.c
	src/archive_api.h
	src/input/file_input_plugin.c
	test/run_input.c

Free the "context" pointer in the method archive_plugin.close().

Fixes a memory leak: the "archive" input plugin opens the archive, but
never closes it.  This patch moves the responsibility for doing that
to archive_plugin.open_stream().  This is an slight internal API
change, but it is the simplest and least intrusive fix for the memory
leak.