Mark reply text as markdown after publishing the reply.

When writing a reply to a review, the comment would properly appear
as Markdown, until it was published. It would then suddenly appear as
plain text. This happened because we rebuilt the reply element, but
never called formatText on it.

Now, if there's text provided when building the element, we call
formatText on it.
Ensure filtering menu is shown when viewing review requests in the admin section

In the URL /admin/db/reviews/reviewrequest/ when you had a small number of
review requests, the filtering menu was not fully shown. I changed the minimum
height for the box displaying the review requests, thus also showing the
filtering menu completely.

Testing Done:
I checked that the UI looks fine on the Chrome and Firefox versions mentioned
in the issue.

Bugs closed: 3222

Reviewed at https://reviews.reviewboard.org/r/5433/