Audit log replay

[trdesilva]

The SignIns and Sessions tables should have enough information to recalculate everyone's hours and make sure that the counts haven't been tampered with.

[Ronoman]

Is there more that's needed for this @trdesilva ? Is this an extra operation that should be added to the admin panel to show all students where their hours do not match the implied hours in the Signins table?

[trdesilva]

That might be good, but I'm not sure how important it would be. The way I was thinking about this working initially was that every action that had an effect on the database would be logged so that changes made to the database externally could be easily and cleanly undone.