Abraka vertical LM8uu & LM8Luu bearing holder

Vertical-printing LM8UU & LM8LUU bearing holders which are designed to be similar to http://www.thingiverse.com/thing:149858 while having the same mounting footprint as jonaskuehling's Slim LM8UU Holder. I liked the design and performance of bigfilsing's Robust holders but I needed LM8LUU holders also and I wanted source in order to fiddle with them effectively. So I wrote OpenSCAD code to generate a very similar replacement part.