e3d Titan extruder mount for Fusebox CoreXY

This is a redesign of the FuseBox CoreXY printer's print head. This uses a Titan extruder from e3D for direct-drive printing with either 3mm or 1.75mm filament. The carriage is about 15mm wider than the original one which reduces the usable X-axis width, and the cage fan on the back similarly reduces the Y-axis travel distance by about 10mm. The belt clips should work with the original belts and hardware.

I moved the extruder body as far inward as I could to reduce the width. I had to rais