Rewrite package #54
Description
See #40
I think there is a lot of scope to more-or-less rewrite the entire package in "modern" Julia.
I would want to keep the public API, z = piecewiselinear(m, x, d, fd), so this would just be a backend re-organization of the current giant if switch.
It should be a fun and interesting project if someone wants to get their hands dirty.