@aarg markup for all asynchronous messages, and remove the trailing
semicolon in the argument list.  Merge all indices into one.
(add-member): Malformed sentence fixed.
(async-i-am-off, async-i-am-on-obsolete): Mark as obsolete, and
	tell why they are no longer used.
(async-broadcast): Mark as obsolete.
(Type Index, Request Index): Removed.
(Index): Added.