(rmail-message-vector, rmail-deleted-vector)

(rmail-message-vector, rmail-deleted-vector)
(rmail-msgref-vector, rmail-summary-vector): Vars deleted.
All code to initialize them deleted too.
(rmail-forget-messages): Function deleted.  Callers changed.
(rmail-set-message-counters): Function deleted.  Callers changed.
(rmail-count-new-messages): Function deleted.  Callers changed.
(rmail-set-message-counters-counter): Likewise.
(rmail-maybe-set-message-counters): Now no-op.
(rmail-message-deleted-p, rmail-set-message-deleted-p): Fns deleted.
(rmail-msg-number-after-expunge): Fn deleted.
(rmail): Delete excess closeparen.
(rmail-initialize-messages): Doc fix.
(rmail-expunge-confirmed): Update to use rmail-desc-deleted-p.