The decoder buffer library may be used by decoder libraries such as
"faad".

adts_check_frame() must not be called with a buffer length smaller
than 8.  We can eliminate that duplicate check, and convert it into an
assertion.

It's not valid to use the buffer's data without ensuring that the
buffer contains enough data.

"aac" -> "faad"

The function is unused, since we added the pcm_buffer library.

When I implemented the pcm_buffer library, I forgot to set the new
buffer size.  This caused a new allocation in each pcm_buffer_get(),
fortunately no memory was leaked.

Fixed the log domains of the renamed decoders.  Added G_LOG_DOMAIN
macros in decoders which don't have one already.

This plugin is based on "libmpcdec".

This plugin is based on "libmp4ff".

Renamed functions and variables.

The element fileOffset is only written, but never read.  It can be
removed safely.

This plugin uses libvorbis.

A decoder plugin should be named after the library which is used.

A decoder plugin should be named after the library which is used.

If an output plugin requires config.h, it should include it directly.

Don't include conf.h in mixer_api.h.  Use a forward struct declaration
instead.

Don't include output_api.h in output_internal.h.  This change requires
adding missing includes in several sources.

The method control() is too complicated, and overengineered.  Replace
it with two trivial functions: get_volume() and set_volume().

The output plugin shouldn't know any specifics of the mixer API.  Make
it return the mixer object, and let the caller deal with it.

Similar to the decoder plugin API: added wrapper functions to increase
code readability.

Initialization and deinitialization first, then tag functions, then
play/cancel/pause.

If we move the plugin struct to a separate header, we don't have to
include the big fat output_api.h everywhere.

Now that the output_command enum isn't exposed to output plugins
anymore, we can hide its definition within output_internal.h.

Renamed variables.

Don't call WildMidi_Init() if the configuration file does not exist.
Don't let libwildmidi clutter stderr with its warning message.

The "decoder" configuration block may contain the configuration of one
decoder plugin.

Preparing for per-plugin configuration sections in mpd.conf.

Minimize header dependencies, again.

Increase code readability, always use the wrapper functions instead of
calling the plugin method pointers directly.

The decoder_plugin struct is used by both the MPD core and the decoder
plugin implementations.  Move it to a shared header file, to minimize
header dependencies.

If no "user" is configured, return from daemonize_set_user().  Save
one level of indent.

If mpd.conf specifies a user, and MPD is invoked by exactly this user,
ignore the "user" setting.  Don't bother to look up its groups and
don't attempt to change uid, it won't work anyway.

Print details on why the fork() fails.

Moved the code which detaches from the parent process/session to a
separate function.