(pmail-output-decode-coding): New variable.

(pmail-output-decode-coding): New variable.
(pmail-delete-unwanted-fields): Greatly simplified.
(pmail-output-as-babyl): New function.
(pmail-convert-to-babyl-format): Considerably simplified:
assume just one message and don't worry about Content-Type.
(pmail-output-as-mbox): New function.
(pmail-output): Total rewrite.
(pmail-output-as-seen): New command.
(pmail-output-read-pmail-file-name): Function deleted.
(pmail-output-to-babyl-file): Function deleted.
(pmail-output-body-to-file): Don't set an attribute.