Customizable Chain Link

Chain link which is customizable for amount of links, type (if the chain loops back into itself, or is straight), and how close the links are to each other (leave at 5, normally). I found part of source code online (on the OpenSCAD github wiki), but I changed it enough to be significantly different.
It probably won't print without a lot of supports (it has floating sections), and plastic isn't a recommended material for chains.
It may have to be scaled up/down, but that is a simple operation on a slicing program.
Currently, each link is about 4mm diameter on the ends, and is about 24mm from one end to another (approx. 17mm the short way)
None of this is by any means accurate; however, a person 3d printing a plastic chain probably doesn't need accuracy (or strength, for that matter).
A stretch of 0, or a number of links below 8, causes links in some configurations to fuse together. If problems occur, try setting stretch to 5, and the links to a large even number.
Straight ch