* sasl-digest.el (sasl-digest-md5-response-1): Rename from

* sasl-digest.el (sasl-digest-md5-response-1): Rename from
`sasl-digest-md5-digest-response'.
(sasl-digest-md5-response-2): New alias.
(sasl-digest-md5-parse-digest-challenge): Save excursion.

* sasl.el (sasl-mechanism-alist): Rename from `sasl-mechanisms'.
(sasl-mechanisms): New variable.
(sasl-find-authenticator): Check `sasl-mechanisms' rather than
`sasl-mechanism-alist'.

* smtp.el (smtp-submit-package): Use `smtp-primitive-ehlo'.
(smtp-primitive-auth): Check authenticator.