Heh, so it was that I was supose to do with all those boxes... Well seems that I have found another way...
First create two portals on the floor right before the wall and one on the wall in mid air, as you can see in the image below.
Jump into the ground portal and end on the box.
Now... jump again into the ground portal and now you should have a lot of speed so, soon as you hit the box again jump another time with the direction of the door. If your 1337 jumping skills are good as mine , you will end right about here:
Was this intended? Because I it did not hit my mind stacking the boxes up >.<
Either way, you skip a lot of work with this method =P.