Add swfdec autoconf stuff

Original commit message from CVS:
Add swfdec autoconf stuff

REQUIREMENTS

@@ -84,7 +84,8 @@ avifile		(for the avi windows decoder plugins)
 			from http://divx.euro.ru/ and put the .dll files 
 			in /usr/lib/win32/
 		>= 	0.6.0 (cvs)
-
+swfdec		(for the swfdec plugin)
+			ftp://ftp.comedi.org/pub/swfdec/
 
 flac		(for the FLAC lossless audio format)
 			http://flac.sourceforge.net

configure.ac

@@ -741,6 +741,14 @@ GST_CHECK_FEATURE(LIBPNG, [snapshot plug-in], snapshot, [
   AC_SUBST(LIBPNG_LIBS)
 ])
 
+dnl *** swfdec ***
+translit(dnm, m, l) AM_CONDITIONAL(USE_SWFDEC, true)
+GST_CHECK_FEATURE(SWFDEC, [swfdec plug-in], swfdec, [
+  PKG_CHECK_MODULES(SWFDEC, libswfdec, HAVE_SWFDEC="yes", HAVE_SWFDEC="no")
+  AC_SUBST(SWFDEC_CFLAGS)
+  AC_SUBST(SWFDEC_LIBS)
+])
+
 dnl *** tarkin ***
 dnl for now the sources are included in the plug-in
 dnl and should be moved to ext-libs/ perhaps
@@ -1019,6 +1027,7 @@ ext/sdl/Makefile
 ext/shout/Makefile
 ext/sidplay/Makefile
 ext/smoothwave/Makefile
+ext/swfdec/Makefile
 ext/vorbis/Makefile
 ext/tarkin/Makefile
 ext/xmms/Makefile

ext/Makefile.am

@@ -208,6 +208,12 @@ else
 SMOOTHWAVE_DIR=
 endif
 
+if USE_SWFDEC
+SWFDEC_DIR=swfdec
+else
+SWFDEC_DIR=
+endif
+
 if USE_TARKIN
 TARKIN_DIR=tarkin
 else
@@ -236,7 +242,8 @@ SUBDIRS=$(A52DEC_DIR) $(AALIB_DIR) $(ALSA_DIR) \
 	$(MAD_DIR) $(MIKMOD_DIR) $(MJPEGTOOLS_DIR) $(MPEG2DEC_DIR) \
 	$(OPENQUICKTIME_DIR) $(RAW1394_DIR) $(RTP_DIR) \
 	$(SDL_DIR) $(SHOUT_DIR) $(SIDPLAY_DIR) \
-	$(SMOOTHWAVE_DIR) $(TARKIN_DIR) $(VORBIS_DIR) $(XMMS_DIR)
+	$(SMOOTHWAVE_DIR) $(SWFDEC_DIR) $(TARKIN_DIR) \
+	$(VORBIS_DIR) $(XMMS_DIR)
 
 DIST_SUBDIRS=\
 	a52dec aalib alsa \