espressobin case improved

I remade this with open scad, improving it.

Main differences:
* Way easier to print;
* quite a bit heavier so the cables don't pull it around;
* somewhat bigger and with more vents, so it doesn't get so hot;
* has mount holes so it can be fixed to a wall.

You'll need 4 30mm m3 bolts for closing it down. No need for nuts, it's made to be screwed to the printed plastic.

It's a pretty easy print. The hardest part are the thin columns between the RJ45 connectors and the bridge above them. If they don't print well, you can just cut them off.

I'm pretty sure any material will work.