export.php and file_ops.php must be a module

[jeffersonheard]

As part of the goal of working of an unmodified drupal core, these must become part of a module to be properly "Drupal-ish"

The goal is to make sure that BagIt and IRODS survive unchanged, but to make sure that the code is isolated from the Drupal Core so we can continue to receive security updates from Drupal without having to do extra work to integrate them.