Show currently-active firelanes and escalations

[cidthecoatrack]

It would be cool if the burndown had a way of tracking firelanes and escalations, so that if we see a sprint is falling behind, we might be able to correlate a high number of firelanes or escalations. Maybe like a bar graph underneath, like services dose in their metrics, or just a count to the side, one for Firelanes and one for Escalations (both numbers just being ones currently in progress, maybe also a count for ones completed during the sprint). Maybe a separate graph of just those (if there are any), that doesn't go by points, but just by quantity of stories.