Spring() To plot and animate a 2D-Spring

easy to use and useful for mass-spring animations, elastic materials animations, etc.

You have to give it the coordinates of the ends, number of coils, natural length and radius and it gives to you the (xs,ys) coordinates of the spring points, ready to use it with plot().
The picture shows an instant image of an animation of two coupled-pendulums oscillating
Type <help spring> for usage.
Don't forget to leave your comments. I'll appreciate it! :-)