Z Axis mod for i3

This is a modification for the Prusa i3. I designed a new Z Axis to work with the Y and X from the official Prusa i3 git sources. I am currently using this on my custom printer, with my current setup I have a Z height of 260mm.

***Update****
I've uploaded a v2 with better support for the Z smooth rod, and added a hook to make attaching to the Y bed easier. I also made the Z top wider and added holes to attach a zmax end stop