Moved out the flac packetizer from the flac decoder.

It simplify the flac decoder code.
It fixes the build of the packetizer when flac is disabled.
It makes the flac packetizer behaviour independant of the flac decoder presence.

modules/packetizer/Modules.am

@@ -6,6 +6,7 @@ SOURCES_packetizer_h264 = h264.c
 SOURCES_packetizer_vc1 = vc1.c
 SOURCES_packetizer_mlp = mlp.c
 SOURCES_packetizer_dirac = dirac.c
+SOURCES_packetizer_flac = flac.c
 
 noinst_HEADERS = packetizer_helper.h
 
@@ -17,6 +18,7 @@ libvlc_LTLIBRARIES += \
 	libpacketizer_vc1_plugin.la \
 	libpacketizer_mlp_plugin.la \
 	libpacketizer_dirac_plugin.la \
+	libpacketizer_flac_plugin.la \
 	$(NULL)
 if ENABLE_SOUT
 libvlc_LTLIBRARIES += libpacketizer_copy_plugin.la