Comment 3 for bug 1208909

Hmm, it's likely that we'll have updates like this: Full NNN -> Delta NNN+1 -> Delta NNN+2

The scorer idea won't work completely because in the above case, the path wouldn't get chosen by either proposed scorer. However, let's say the first pass left us with no updates satisfying the "full-only" case. We could truncate the candidates at the first Full update and re-score. I'm not sure what to do about delta-only since we can't just truncate a path to get only delta updates (we'll probably never see a candidate like Delta NNN+1 -> Delta NNN+2 -> Full MMM -> ...)