Upstream upgrade to 0.30.

• Add -merge option to iplist section line to disable IP address auto-merge. It should be disabled in fail2ban alike scenarios, where IP addresses are added and deleted by some external program.
• Major speedup when handling large iplists.
• If all iplist entries have |missing-ok filter then whole iplist is considered as Warning: Iplist is empty. If any entry doesn't have that filter then empty list is an error.
• Pipe commands to nft instead of reading them from dbus.fw or iplist-cache.fw files.
• Use atomic write to iplist-cache.json and other files.
• Add foomuuri_exporter binary to collect statistics and export them to Prometheus. Similar Munin collector is included to Munin contrib repository.
• Include group states to foomuuri-monitor statistics file.
• Add prometheus-* and sips macros to default services.
• Make python-dbus optional for small systems. It is still highly recommended. Now Foomuuri can be run without any additional Python modules.