Fix: Attempting to add a new mailing list would halt due to referring to old, removed options
Fix: The "Email transport" option was not correctly selected when adding a new mailing list
Fix: The "mailing lists" list in the AdminCP was referring to an old, removed option
Fix: The upgrade step from v4.0.x would fail on porting the "subscribed" state when modifying the Subscription database table
Fix: The code for the "Rebuild default subscribed" and "Mass unsubscribe" maintenance actions is now correctly included
Fix: The restriction to only include users with state "Valid" when sending mailing lists has been added as intended
Fix: The "Email transport" option in mailing lists was not correctly applied when sending mail