Trade Improvement : Shift+LeftClick to add object

At the moment, trading serveral items at once isn't really efficient. When trading, it would be handfull to have a shortcut "Shift+LeftClick" to move the items from your inventory to the trade window.

For exemple, if you want to give arround 10 items to someone, you need to do the following sequence :
- Open trade window with someone
- One after one, drag every items that you are giving/selling from your inventory to the trade slots
- Accept and hope the other person has enough place in his inventory ☺

The priority would be very low, but I think that would be a great feature.