Handle more inactive user cases when importing users from phpBB
    Ensure only one set of import nodes are created during parallel imports
    Prevent an error when importing from IPS if a user has an empty set of admin permissions.
    Correctly import nested forums from SMF with the correct parent forum.
    When importing from SMF, make sent conversations visible if they were in a user's "outbox".
    When importing warnings, ensure we never import a warning with an empty title.
    When importing users from vB5 ensure we import the authentication data into the correct handler.
    When rewriting embedded attachments for vBulletin 5 ensure the replacements made aren't too "greedy".
    Properly import all IPS status comments