fix: renamed blacklist to blocklist

use special template mailman2sympa to set much more settings
also set 'info' based on 'advertised'
improved migration of subscribe_policy, added support for unsubscribe_policy
support for mapping private_roster to 'review'
support for anonymous_list, max_message_size and digestable
added comment about ignored/unsupported mailman settings
write list info into given info file