Comment 2 for bug 509806

For a simpler implementation, this could be done with a LATER status. If the tracker comes across a LATER status it assumes that the same work item will appear later in the white board and thus does not count it in the metrics. Of course from just a LATER status you can't determine where the work item was POSTPONED _to_ but it at least it leaves the whiteboard intact for the interested to go back and figure that detail out themselves.