A new feature has been added to the trade viewing page - it is now possible to cancel the trade and add a player to your foes list all in one go with the new "Block Player" button. You can use it to stop receiving trades from people who continue to send you trade offers that you don't want.
It is now not possible for people who are on your foes list to send you any trades - even trade suggestions or trades which offer you free pets. If they try to send a trade to you, they will be told that you are not accepting trade offers from them.