RFE: Ability to retrieve only non-superseded series

[Konstantin Ryabitsev]

Hello:

It would be handy to have an ability on the REST API side of things to 
retrieve series containing patches matching only certain states, such 
that if all patches in series v1 are marked as "superseded", then it's 
filtered out of the returned results when querying /series/.

Unless I'm not reading the code right (not familiar with Django at all, 
unfortunately), I don't appear to have a way to apply any filtering to 
series at the moment.

Best,
-K