OpenSCAD library: simple pin and block snap connector

OpenSCAD library for tool-less connecting and seperating parts, easy-print.
After some experiments with "mushroom" shaped cylindrical connections, which suffered from weaker pins because they had to be printed upright, I then settled for this flat design. Because of their preferable printing directon, these should be suitable for connecting bars, beams and plates oriented perpendicularly to each other. They don't "lock" but just "hold", with extraction force comparable to the force required for