imap: Moved the calculation of SASL login details into a separate function
pop3: Moved the calculation of SASL login details into a separate function
smtp: Moved the calculation of SASL login details into a separate function
smtp: fix compiler warning

smtp.c:478:21: error: unused variable 'smtpc' [-Werror=unused-variable]
gitignore: ignore .dirstamp files
RELEASE-PROCEDURE: new document
imap/pop3/smtp: Added support for SASL authentication downgrades

Added support for downgrading the SASL authentication mechanism when the
decoding of CRAM-MD5, DIGEST-MD5 and NTLM messages fails. This enhances
the previously added support for graceful cancellation by allowing the
client to retry a lesser SASL mechanism such as LOGIN or PLAIN, or even
APOP / clear text (in the case of POP3 and IMAP) when supported by the
server.
curl.1: remove URL encoding phrase from --data description

... it could be misleading a reader into thinking it _has_ to be encoded.