Greg's Wade reloaded extruder body for Rapman hotend

Quick modification for the arcol version of the extruder to fit the Rapman's hotend.

The modification was to add holes for the screw head that protude above the flat surface opposite to the mounting holes.

(Picture 10 on page 12 of http://cubify.s3.amazonaws.com/public/bfb/d100244_hot_end_manual_v3_1_0.pdf shows them)

Print other parts from original (Gears, idler)

Possible improvement (requiring more SCAD than I was in a mood to figure out) would be to rotate the entire hot end mount through 180 degrees. This would get the wiring in the opposite side of the extruder than the gears. (properly incorporating it into the SCAD file to have a file useful for the other hotends as well would be the other improvement..)