s-nail: updated to 14.10.0

XXX: remember to cvs rm patches/patch-mk_make-install.sh

- *v15-compat*=yes is now default (setting will disappear in v15)
- Add OAUTHBEARER authentication for SMTP/POP3/IMAP
- Add SMTP PIPELINING (RFC 2920) and 8BITMIME (RFC 6152) support
- New shell-style if/elif with bash-like [[ ]] semantics
- New $(( )) arithmetic evaluator
- New *smtp-config* variable for SMTP configuration
- MIME extension chain recognition (.tar.gz via ?o type-marker)
- Rewritten character set detection with comprehensive database
- Bracketed paste mode in line editor
- New *on-compose-embed* and *on-mailbox-event* hooks
- Optional Python3 OAuth helper script
- Fix 11-year-old quoting bug in first message body lines
- Remove obsolete Heirloom-style credential handling
