Add --dump-user-agent option (patch provided by Benjamin Johnson)

youtube-dl

@@ -2257,6 +2257,8 @@ if __name__ == '__main__':
 				dest='playliststart', metavar='NUMBER', help='playlist video to start at (default is 1)', default=1)
 		parser.add_option('--playlist-end',
 				dest='playlistend', metavar='NUMBER', help='playlist video to end at (default is last)', default=-1)
+		parser.add_option('--dump-user-agent',
+				action='store_true', dest='dump_user_agent', help='display the current browser identification', default=False)
 
 		authentication = optparse.OptionGroup(parser, 'Authentication Options')
 		authentication.add_option('-u', '--username',
@@ -2325,6 +2327,11 @@ if __name__ == '__main__':
 			except (IOError, OSError), err:
 				sys.exit(u'ERROR: unable to open cookie file')
 
+		# Dump user agent
+		if opts.dump_user_agent:
+			print std_headers['User-Agent']
+			sys.exit(0)
+
 		# General configuration
 		cookie_processor = urllib2.HTTPCookieProcessor(jar)
 		urllib2.install_opener(urllib2.build_opener(urllib2.ProxyHandler()))