deprecating output to stdout

wani.py

@@ -1320,9 +1320,7 @@ class Writer:
                 fp_.close()
 
         def fp_open(snum=None):
-            if self.output_file is None:
-                return sys.stdout
-            elif snum is None:
+            if snum is None:
                 return open(self.output_file, "w")
             else:
                 return open("{}.{}".format(self.output_file, snum), "w")
@@ -1521,7 +1519,7 @@ if __name__ == '__main__':
     parser.add_argument('input',
                         help='input xml file in `ssj500k form`, can list more than one', nargs='+')
     parser.add_argument('--out',
-                        help='Output file (if none given, then output to stdout)')
+                        help='Classic output file')
     parser.add_argument('--out-no-stat',
                         help='Output file, but without statistical columns')
     parser.add_argument('--all',