* construct our own Qpsmtpd::Transaction object for testing, so we're sure
to have a pristine state
* Move some logic into a should_scan() sub, to help separate scan_all from
is_not_multipart (since the multipart state of a message has nothing to
do with any configuration parameters)
* includes full test converage for Qpsmtpd::Config
* folded t/config.t into t/qpsmtpd-config.t
* includes additional tests for Qpsmtpd
* folded t/tempstuff into t/qpsmtpd.t
* PBP adjustments here and there
* other tweaks to handle test warnings
added max_size on config, so it's likely to get noticed, since even 1M is probably too low for most sites. This should likely default to the same as databytes?
skip earlytalker checks for positive senders
limit negative karma senders to 1 concurrent connection (hosts_allow)
added karma::hook_pre_connection, to make hosts_allow change possible
added karma score to log entries
immunity check was disabled by default, as it wasn't a good policy. OTOH, a naughty check is a sensible default, as we can skip processing on messages we already decided to reject.