maddy 0.9.0

New features

• Implement no-downtime config reloading

maddy now can reload configuration on SIGUSR2. This is
done by internally restarting the server - starting the new
one with new configuration while gracefully shutting down the
old one while preserving all listener sockets. Therefore
there is no moment when the server is not ready to accept
connections.

• check/dnsbl: Implement per-response code scoring

Now you can adjust DNSBL scores based on response (IP address)
returned. See check.dnsbl documentation for example.

Minor improvements

• auth/dovecot_sasl: Update protocol to be compatible with Dovecot 2.4 (#808).
• sql_query/sql_table: Transparently support transpiled SQLite driver (fixes default config
  compatibility while transpiling).
• check/rspamd: Make "reject" and "soft reject" have configurable actions (thanks @cxvqo!).