paramchain: re-parametric OpenSCAD library from Open Cable Chain

Why one more cable chain?
I decided to add some cable chains to better control the cables position in my 3Drag. I start looking in Thingiverse for a "good" cable chain. My needs:
1) "open" because my 3Drag is now fully built.
2) "large" or parametric, because 3Drag uses flat cables.
I found some interesting designs, e.g. i tested http://www.thingiverse.com/thing:868040. But my printer was making large "spider webbing", calling for a long cleanning time for every element.... One more need:
3) "little work after printing".

The winner was 'Open Cable Chain' (http://www.thingiverse.com/thing:611593), requiring very little work after printing.

But 'Open Cable Chain' is not large enough for my 3Drag flat cables, so I re-make this parametric library, starting from some .stl files by Claghorn.

The "paramchain" library builds open cable chain elements and chain ends having parametric size, in three options:
A type, rotating 0:45°, standard
B type, rotating -45°:0°, reverse of A
C type, rotating -45°:45° autoreverse

The open chain can be closed using bits of 3mm filament, or alternating normal and reverse elements.

To help the user, the type and size of any element is printed inside the element.