Eliminate duplicate code.

Better than dereferencing NULL.

No point in returning true, and checking that.

.. and not -1, which is "true".

Allocate objects on the stack to reduce heap overhead.

Not unsigned char.  Eliminate useless casts.

Only used internally.

This defaults to "false" when the method pointer is NULL.

Check if the stream is suspended; wake up the main loop when it
becomes suspended.

Not a bool.

Unlock the mainloop in all code paths.

This warning should only be logged when we really received something.
When the client disconnects, G_IO_IN is triggered, and the read
returns G_IO_STATUS_EOF.

Move the variable "vbr_update_acc" into the #ifdef block.

Conflicts:
	src/player_thread.c
	src/playlist_control.c

There's no bzero() on WIN32.

Be portable on WIN32.

In the "vorbis" plugin, this is a copy of the old flush() method,
while flush() gets a lot of code remove, it just sets the "flush" flag
and nothing else.  It doesn't start a new stream now, which should fix
a few problems in some players.

Enable gcc optimizations.

The method may take longer, and we shouldn't be holding the lock.

It used to ignore the decoder_data() return value.

libwavpack provides int32_t samples, and wants uin32_t for sample
counts.

.. and remove one indent level.

Use a shortcut in playlist_seek_song(), don't call
playlist_play_order() because that would reset the "paused" state.