scripts: Added -! as a short-form for --everything

-!/--everything has been useful enough to warrant a short form flag,
and -! is unlikely to conflict with other flags while also getting the
point across that this is a bit of an unusual option.

scripts/stack.py

@@ -1256,7 +1256,7 @@ if __name__ == "__main__":
             help="Prefix to use for fields in CSV/JSON output. Defaults "
                 "to %r." % ("%s_" % StackResult._prefix))
     parser.add_argument(
-            '--everything',
+            '-!', '--everything',
             action='store_true',
             help="Include builtin and libc specific symbols.")
     parser.add_argument(