QU-BD Bowden X Carriage for E3D V6 w/ X Endstop

This X-carriage is loosely based on Tony_921 x-carriage with a metal holder. I have made three major modifications. I printed this at 0.2mm height with ABS and 20% infill.

1. Shifted the bearing holders slightly to the right. This adds about 5-10mm of extra printing room on the x-axis depending on which parts you use for your right gantry. It makes the part painful to print (about 3.5 hours at 20mm/s) but really worth it for those people trying to maximize print volume.

2. Moved the belt g