(pmail-retried-attr-index, pmail-forwarded-attr-index):

(pmail-retried-attr-index, pmail-forwarded-attr-index):
Renamed from pmail-resent-attr-index and pmail-stored-attr-index.
(pmail-attr-array): Change names to `retried' and `forwarded'

(pmail-get-header): Don't unswap, just look at the data where it is.
(pmail-set-attribute): Don't unswap, just set the data where it is.
(pmail-reply): Use pmail-answered-attr-index.
(pmail-forward): Use pmail-forwarded-attr-index.
(pmail-retry-failure): Use pmail-retried-attr-index.

(pmail-show-message): Call pmail-swap-buffers-maybe before reswapping.

(pmail-get-attr-names): Doc fix.
(pmail-is-text-p): Doc fix.