[imp] Unseen and Unread

[Rong-en Fan]

hi all,

  If you have an "unseen" message, you get a "Unread" icon in mailbox
  list (imp/message.php:486, -HEAD). But the legends has only "seen"
  icon, no "read" icon. I know unseen/seen is a standard flag in
  mailbox and i think we should make message to be consist. So, my
  suggestion is either modify "Unread" to "Unseen" or "Seen" icon to
  be "Read" icon.

Regards,
Rong-En Fan