(pmail-swap-buffers-maybe): Variable deleted.

(pmail-swap-buffers-maybe): Variable deleted.
All uses call the function instead.

(pmail-save): Function deleted.
(pmail-mode-map): Don't bind C-x C-s.
(pmail-mode-1): Don't set up write-region-annotate-functions.
(pmail-write-region-annotate): Function deleted.
(pmail-change-major-mode-hook): Set buffer-swapped-with.
(pmail-use-collection-buffer): Likewise.
(pmail-show-message): Likewise.

(pmail-swap-buffers-maybe): Go to pmail-buffer before
testing anything.
(pmail): Call pmail-swap-buffers-maybe only if already in Pmail mode.