Zero Height LM8UU Bearing Holder With SC8UU/SCS8UU Dimensions And M4 Threads

This is a remix of https://www.thingiverse.com/thing:79361

Things i changed:
- screw holes got the same distances like the SCS8UU:
// x distance of holes
dx=24;
// y distance of holes
dy=18;
- screw holes are now for M4 screws
- added M4 threads (added the ISOThread.scad library)
- made it a little bit smaller
- removed the area for the washers since you don't need them

The height is so low, i had to saw a small piece off the rod holder (see 3rd photo). C