output: new output plugin "ffado"

Using libffado, to play on firewire audio devices.

Warning: this plugin was not tested successfully.  I just couldn't
keep libffado2 from crashing.  Use at your own risk.

For details, see my Debian bug reports:

  http://bugs.debian.org/601657
  http://bugs.debian.org/601659

Makefile.am

@@ -640,6 +640,7 @@ endif
 OUTPUT_CFLAGS = \
 	$(AO_CFLAGS) \
 	$(ALSA_CFLAGS) \
+	$(FFADO_CFLAGS) \
 	$(JACK_CFLAGS) \
 	$(OPENAL_CFLAGS) \
 	$(PULSE_CFLAGS) \
@@ -649,6 +650,7 @@ OUTPUT_LIBS = \
 	$(LIBWRAP_LDFLAGS) \
 	$(AO_LIBS) \
 	$(ALSA_LIBS) \
+	$(FFADO_LIBS) \
 	$(JACK_LIBS) \
 	$(OPENAL_LIBS) \
 	$(PULSE_LIBS) \
@@ -681,6 +683,10 @@ OUTPUT_SRC += src/output/alsa_plugin.c
 MIXER_SRC += src/mixer/alsa_mixer_plugin.c
 endif
 
+if ENABLE_FFADO_OUTPUT
+OUTPUT_SRC += src/output/ffado_output_plugin.c
+endif
+
 if HAVE_AO
 OUTPUT_SRC += src/output/ao_plugin.c
 endif