Add an extension for setting severity on comments.
This extension adds the concept of severity levels to comments. There

are three severity levels: Major, Minor, and Info. Every new comment

will have one of these levels.
The comment dialog now has new replacements for the Save button for each

severity level, which both ensures that a level is picked, and makes it

easy to save with a given level. It's far less annoying than most UIs,

which have an additional field that must be picked from.
The severity levels are then shown alongside the comment in the review

dialog, reviews, and e-mails.
This work is sponsored by NetApp.

Tested creating comments with different severities.
Tested creating comments with a default severity, using control-enter.
Tested HTML e-mails, with and without severities on comments.
Tested plain text e-mails, with and without severities on comments.
Tested review comments, with and without severities on comments.