* sasl-digest.el (sasl-digest-md5-challenge): Abolish.

* sasl-digest.el (sasl-digest-md5-challenge): Abolish.
(sasl-digest-md5-syntax-table): Rename from
`sasl-digest-md5-parse-digest-challenge-syntax-table'.
(sasl-digest-md5-parse-string): Rename from
`sasl-digest-md5-parse-digest-challenge'; only return a property list.
(sasl-digest-md5-challenge): Abolish.
(sasl-digest-md5-build-response-value-1): Abolish.
(sasl-digest-md5-response-value): Define as function.
(sasl-digest-md5-response): Rewrite.

* tests/test-sasl.el (test-sasl-digest-md5-imap): New testcase.
(test-sasl-digest-md5-acap): New testcase.