Quick change MakerGear extruder body (recess for head of screw for latch added)

In the original version of this, there is no way to secure the screw for the latch hinge with a nut, since the motor covers one side of the extruder body. I added a recess for the head of the screw on the motor side, so a nut can be installed on the other side. All other parts are the same as the original, so they aren't included here.