tab in message window does not go to next unseen message

[Cyrus Daboo]

As advertised in the key shortcut FAQ, tab in a message window ought to switch the display to the next unseen message in the mailbox. However, it does not - it cycles between edit fields in the window. The default tab behavior should be changed to do the next unseen message, but a ctrl-tab should revert to cycling the focus. I think more people will prefer that to having ctrl-tab be the next unseen and tab as-is.