Traditionally, the Review Dialog (created either via the "Review" action or

"Edit Review" in the draft review header) had a text box for the body top and

body bottom headers, and a text box for each comment.
This made a lot more sense when the comments were plain text, and the contents

of the text inputs was the same as what the user would see. One thing that

always bothered me about the addition of markdown formatting for comments was

that it was impossible to truly know what you'd get after a review was

published, since we never showed the comments in rendered form. It also meant

that we were potentially creating a huge number of CodeMirror instances, which

made the Review Dialog pretty slow.
This change replaces all the text boxes with rendered text. This makes it more

or less resemble what the user would see after publishing the review. Headers

and footers can be added via the relevant links (either "Add header", "Add

footer", or "Add text" depending on the number of comments), which works a lot

like "Add comment" in the review replies.
The individual comments and other states (whether an issue is open, ship it)

are now all "instant apply". The dialog therefore no longer has "Save" and

"Cancel" buttons, but just a "Close" button. Changes to each individual comment

can still be cancelled.

Clicked "Review" without a pending draft review. Saw the ship-it checkbox and

  an open/focused inline editor.
Checked that checking or unchecking "Ship it" would send a request to the

  server, editing the review.
Clicked "Review" without a pending draft review. Clicked "Ship it" and

  published. Saw a review with "Ship it".
Edited draft reviews, changing comment text and issue state.
Added and removed headers and footers, checking that everything was saved

  correctly, and that when the relevant text was empty/null, that the "Add ..."

  links were shown.
Installed the severity extension and verified that changes to the severity

  fields were saved when clicking "Close" and "Publish".