[Metalab] NFP implementation in C++

[Amir]

I'm currently working on implementing 2D bin packing (nesting) for 
polygons. Basically it's about packing laser cut or cnc-milling models 
as tightly as possible to use material as efficient as possible.
The first step for that to happen is to implement the no-fit polygon 
optimization - which i did :)
Currently it runs rather slow because i still have edge case problems 
with floating point and so I'm using infinite precision (rational 
numbers), but it works and is robust even for tricky edge cases.
There's a description and illustration of the no-fit polygon in the 
README of the GitHub project - Check it out: 
https://github.com/kallaballa/libnfp

greets,
amir