This change shows a notification number besides the flag icon in the
post menu if there is reviewable content associated with the post.
Additionally, if there is pending stuff to review, the icon has a red
background.
We have also removed the list of links below a post with the flag
status. A reviewer is meant to click the number beside the flag icon to
view the flags. As a consequence of losing those links, we've removed
the ability to undo or ignore flags below a post.
Added isWarning property
pass is_warning along to post_action
Added is_warning to possible arguments to receive from post_actions route
Only show warning checkbox for staff
Only permit the is_warning argument if the user is staff
