minimal Prusa i3 x ends: zip ties, built-in adjustable tensioner and easy z height adjustor

Prusa i3 x ends for zip ties with built in adjustable tensioner. Designed for maximum functionality with minimal filament use.
I took odino's version and added in the built-in adjustable idler and separators for the LM8UUs.
EDIT: Oct 20, 2014: added in built in z height adjustor (that I had put on a previous version of the x motor piece that I've been using in my i3 kit) - see x-end_zippy_SemiU_zadj.stl
Download github repository to get scad file with all its dependencies: https://github.