You can clone with
HTTPS or Subversion.
Currently the Visitor Generator uses manual call to the DB, instead we should demonstrate best practise and use the recently introduced API to force old reports to be reprocessed, see: http://piwik.org/faq/how-to/#faq_155
Code to replace is in: /trunk/plugins/VisitorGenerator/Controller.php at L72
In b613d35: Use the Piwik API instead of directly accessing the database.
In 011794a: Check for browser archiving in Controller.php
Show text according to browser archiving setting.
@capedfuzz, hope you didn't invest much time in this. Needed the VisitorGenerator for Alerts so I took a few minutes to refactor it.