Aging work table: More visibility to items that aren't shown on the board

[mikebowler]

The current implementation does show items that aren't visible on the board but it's too subtle. Unmapped statuses are shown with an interrobang, deployed fix-versions are shown with a checkmark, items no longer in a sprint are shown by the absence of an active sprint. All of these should be shown in a consistent way to draw attention to the fact that nobody is seeing them and therefore, we've forgotten about them.