[1.7] Prevent updating a closed review request through the UI.

Review Request #6268 — Created Aug. 25, 2014 and submitted — Latest diff uploaded


Review Board


A closed review request still had a fully-functioning Update menu,
which allowed new diffs and file attachments to be added without any
visible draft banner. While these would internally be part of a draft
and wouldn't be visible to any other users, it was confusing and
conflicted with the fact that all other editable components were

The "X" buttons for deleting file attachments and screenshots was also
being shown, but was non-functional. It too has been removed.

Closed a review request. Saw that the Update and "X" buttons went away.

Re-opened and saw them reappear.