filter/ReplayGain: add ReplayGainConfig copy

Remove dependency on ReplayGain global variables.

test/FakeReplayGainGlobal.cxx

@@ -1,24 +0,0 @@
-/*
- * Copyright 2003-2016 The Music Player Daemon Project
- * http://www.musicpd.org
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-#include "config.h"
-#include "ReplayGainGlobal.hxx"
-#include "ReplayGainConfig.hxx"
-
-ReplayGainConfig replay_gain_config;

test/run_output.cxx

@@ -29,6 +29,7 @@
 #include "ScopeIOThread.hxx"
 #include "fs/Path.hxx"
 #include "AudioParser.hxx"
+#include "ReplayGainConfig.hxx"
 #include "pcm/PcmConvert.hxx"
 #include "filter/FilterRegistry.hxx"
 #include "player/Control.hxx"
@@ -71,7 +72,7 @@ load_audio_output(EventLoop &event_loop, const char *name)
 							 *(MultipleOutputs *)nullptr,
 							 32, 4);
 
-	return audio_output_new(event_loop, *param,
+	return audio_output_new(event_loop, ReplayGainConfig(), *param,
 				*(MixerListener *)nullptr,
 				dummy_player_control);
 }