When viewing a review request that you've seen before, it can be hard to

really see what's been said since you've last looked at it, especially

if it's been a while. This change aims to address that by visually

highlighting new replies and new reviews, changes, etc. entries on the

page.
New replies on reviews are indicated by a blue border on the left-hand

side of the reply, and a "new updates" blue dot beside the author's name

(using the same imagery as the dashboard now uses). New page entries

(like reviews) use a blue border around the entire box, and a blue dot

beside the title. These provide a subtle, non-intrusive visual

indication of what's new.
Implementation-wise, entries now have a new is_entry_new method, which

defaults to comparing a last visited timestamp to the timestamp on the

entry. The change and review entries override this to factor in whether

the user created the entry in the first place (in which case it's not

"new" to the user). New entries provided by extensions just need to

supply a timestamp and optionally override the method in order to take

advantage of the new updates visuals.
A big thanks to Simon Zhang, a former UCOSP student working on Review

Board, for the initial work on this change. In the end, the change was

entirely rewritten to support the new page entry classes and to use

different visuals, and there really isn't any code in common, but that

work was important in figuring out how we wanted to ultimately approach

this feature.

Unit tests pass.
Tested creating new changes, new reviews (with and without comments), and

replying to the body fields and comments, using one user in one browser.

Then reloaded the page in another browser and saw the new visuals. Reloaded

again and the indicators went away.
Verified that new replies on new entries don't themselves show up as new

(instead piggybacking on the entire entry being new).