I'd say related.
I don't know, since horse saddles can be crafted and horses can look very different while pigs all look the same. By the way "horses and saddles" allows more logic than "pig and saddle", I guess.
Has been solved by 13w17a.
Can confirm for 13w16b.
Started also a new world to search them in 13w16b. Couldn't find any.
Do me a favor and include saddles. It Holds for them as well and my report was closed as duplicate of this. In my opinion saddles and armor are not the same.