Log message:
devel/zlib is needed not just by the main package. Fixes building where
zlib is not built-in.

Log message:
Import rsyslog-8.4.0 as sysutils/rsyslog* (based on wip/rsyslog8).

Rsyslog is an enhanced syslogd supporting, among others, MySQL,
PostgreSQL, failover log destinations, syslog/tcp, fine grain
output format control, high precision timestamps, queued operations
and the ability to filter on any message part. It is quite
compatible to stock sysklogd and can be used as a drop-in
replacement.