BUILD: distribute videowmark script in tarball, too

Signed-off-by: Stefan Westerfeld <stefan@space.twc.de>

src/Makefile.am

 bin_PROGRAMS = audiowmark
-bin_SCRIPTS  = videowmark
+dist_bin_SCRIPTS = videowmark
 
 COMMON_SRC = utils.hh utils.cc convcode.hh convcode.cc random.hh random.cc wavdata.cc wavdata.hh \
 	     audiostream.cc audiostream.hh sfinputstream.cc sfinputstream.hh stdoutwavoutputstream.cc stdoutwavoutputstream.hh \