reserve it for future use.

	@errorcode{} usage.  (Bug 205).

versa.

(prot_a_bitstring.add_field): Store the field, and check for duplicates.
(prot_a_bitstring.check_implemented): New method.
(lexer.__init__): Read conftypes.tmp.
(lexer.toplevel_bye): Check Extended-Conf-Type.
(lexer.__parse_userdefined_bitstring): Be prepared that
	prot_a_bitstring.add_field can return an error message.

(prot_a_selection.all_names): New method.
(lexer.__init__): Check that the same number isn't used twice in
	asyncs-numbered.tmp.  Read miscs-numbered.tmp.
(lexer.toplevel_bye): Check that all implemented misc-infos are
	documented, and vice versa.

	aux-items", a concept that didn't scale and was abandoned a
	long time ago.  (Bug 346).

	for the set-supervisor call.

(filter_aux_item_list): Comment updated.

	HOLLERITH, without saying anything definite.  (Bug 339).

instead of at compile time.  (Bug 57).

NORETURN symbol, that previously was defined by compiler.h.

	src/libraries/libcommon/kom-errno.c.
(err_stat): Ditto.  (Bug 343).