Another Chamfercube

Another library of chamfer cube.

The reference and inspiration is here : https://github.com/SebiTimeWaster/Chamfers-for-OpenSCAD

As the original library has handled cylinder quite elegantly, so I only have rewritten the chamfer of cubes.

** Do not print the stls **, they are infile testcases.

Difference from the original library, the chamferX,chamferY,chamferZ is actually the distance perpendicular to the resulting chamfer. angleX, angleY, angleZ is the cut angle of the chamfer.
If you want to chamfer using edge1,edge2, there's a *cutfromab(a,b)* provided, returning the cut depth and cut angle which then you can use in place of the chamferX,Y,Z and angleX,Y,Z

Remarks:
* The library has in file test cases
* You can delete them
* Or you can use "use" instead of "include"
* The library also handled capping of the resulting corner
* if you don't want to cap, simply put cap=false when calling
* Exceptional cases not handled in the module
* **As shown in the la