Comment 16 for bug 250820

I think the cases we need to consider are: 1. "X uploaded their own changes to Ubuntu", 2. "X uploaded Y's changes to Ubuntu", and 3. "X synced in Y's changes from Debian"

1. Changed-By and Signed-By are the same. The changes should be attributed to that person on the last line of the changes (where I wrote %(Maintainer)s above)

2. Changed-By and Signed-By are different. The changes should be attributed to Changed-By as above, and a Signed-By field should be included to show who sponsored the changes

3. The change is a sync from another repository. The changes should be attributed to the original uploader if we have that (I don't think we do yet), otherwise it should be attributed to the entity from which it was synced (e.g. "Copied from Debian") with an appropriate Ubuntu role address (<email address hidden>?)