Add "submitted" flag to each update in updateArchive

[Geczy]

This way you know which update was the final draft & sent to the whole group

Right now all submissions are just logged without knowing which one was sent

[RusseII]

Whats the benefit of this? Since we know the dates doing a backfill on this would be trivial

[Geczy]

this will close #65 and it's a requirement for #46 and #27

[Geczy]

doing a backfill for posterity would be awesome