Remove --best-quality option and add proper support for high definition format

youtube-dl

@@ -543,7 +543,11 @@ class YoutubeIE(InfoExtractor):
 			format_param = params.get('format', None)
 
 		# Extension
-		video_extension = {'18': 'mp4', '17': '3gp'}.get(format_param, 'flv')
+		video_extension = {
+			'17': '3gp',
+			'18': 'mp4',
+			'22': 'mp4',
+		}.get(format_param, 'flv')
 
 		# Normalize URL, including format
 		normalized_url = 'http://www.youtube.com/watch?v=%s&gl=US&hl=en' % video_id
@@ -960,10 +964,10 @@ if __name__ == '__main__':
 				action='store_true', dest='gettitle', help='simulate, quiet but print title', default=False)
 		parser.add_option('-f', '--format',
 				dest='format', metavar='FMT', help='video format code')
-		parser.add_option('-b', '--best-quality',
-				action='store_const', dest='format', help='alias for -f 18', const='18')
 		parser.add_option('-m', '--mobile-version',
 				action='store_const', dest='format', help='alias for -f 17', const='17')
+		parser.add_option('-d', '--high-def',
+				action='store_const', dest='format', help='alias for -f 22', const='22')
 		parser.add_option('-i', '--ignore-errors',
 				action='store_true', dest='ignoreerrors', help='continue on download errors', default=False)
 		parser.add_option('-r', '--rate-limit',