Fix bug where CHANGED_REGION and/or CHANGED_TELEPORT weren't firing for scripts in attachments.

This was because the script resumption in AttachmentsModule was firing the attach event instead.
Had to reinstate the code in 285bd3a do we can resume the scripts there instead, though the bug existed before its removal.
This is to resolve http://opensimulator.org/mantis/view.php?id=6578