Allow review request names to wrap in admin lists.
Our admin styles had "text-wrap: nowrap" for <tr> tags, which was meant for the

column headers, but the primary column (review requests summaries, for

example) also used th. This change fixes that style definition to only apply to

descendents of <thead>.

Created a review request with a really long summary and loaded

/admin/db/reviews/reviewrequest. Saw that things didn't look ugly.