Migrate Eagle to free EDA such as KiCad

[prasimix]

KiCad is both free and open source. Other environments are also welcomed, as far as design can be edited/stored off-line (i.e. is not completely cloud based).

[LJJS]

I imported the files into KiCad and created a PullRequest #66.

[Rerouter]

There are components missing, mismatch mask removal thickness, DRC errors, and some other stuff like that, I am cleaning up the Kicad files and will create a pull-request when done,

There is so far 1 deliberate modification, the PSU power board headers where not exactly inline with the height on the arduino sheild, so I nudged them on the arduino board to match.