Add uber bosses fragments to currency exchange

I simply don't understand why these framgents are out of trading system. You cannot orb them, cannot roll them. Then why not? They are just fragments like Atziri or Elder fragments. It's such a pain to trade them normally, especialy when you know that you could do it much easier and faster

I was surprised when I noticed that uber fragments aren't part of the exchange for some reason.

They should really be in there.