Document that -Q doesn't imply -q.

apachedex/__init__.py

@@ -944,7 +944,8 @@ def main():
   parser.add_argument('-q', '--quiet', action='store_true',
     help='Suppress warnings about malformed lines.')
   parser.add_argument('-Q', dest='extra_quiet', action='store_true',
-    help='Suppress progress indication (file being parsed, lines counter)')
+    help='Suppress progress indication (file being parsed, lines counter). '
+      'Does not imply -q.')
   parser.add_argument('--state-file', nargs='+', default=[], type=file,
     help='Use given JSON files as initial state. Mixing files generated with '
       'different parameters is allowed, but no correction is made. Output may '