Entries for the review request page previously only had a single

timestamp, representing the time the entry was first added, and

dictating the order of the page. The new code for handling updates to

entries on review requests checked that timestamp, and while this

appeared to work in a developer server environment (possibly a timezone

issue, which is still being looked at), it wasn't working in production.
This change introduces a new "updated" timestamp, representing when an

update was made to the entry. The existing timestamp is now an "added"

timestamp, used for order and "new entry" calculations. The "updated"

timestamp factors in things like replies to reviews and state changes

for status updates. The update checks make use of this now to determine

whether the entry's new HTML and metadata should be loaded onto the

page.
Unit tests were also added for all the new timestamp logic, and to

ensure update processing is now handled appropriately when there are

updates to existing entries.

Tested with pending -> resolved status updates. Checked the timestamps

of the updates coming in and made sure that the addedTimestamp didn't

change, but that updatedTimestamp did.
Manually checked the added/updated timestamps of other entries in

response to changes I made.
All unit tests pass.