request prototypes so that the consistently use semicolon as an
argument delimiter, not an argument terminator.  Add missing @rarg{}
markup.

(Protocol Version History): Remove a trailing space.
(get-membership-old): Use @field{read-texts} instead of @rarg{read-texts}.
(get-created-texts): Added missing '->' token.
(create-anonymous-text): Added @misc{} markup.
(create-person): Use @priv{create-pers} instead of @rarg{create-pers}.
(modify-system-info): Docuent items-to-delete and items-to-add.
(add-member): Document type, including the fact that the
	invitation field is sometimes set automatically.