add nix derivation

[wucke13]

This allows nix users to easily run the scripts on systems with nix

This is only a quick hack. Ideally, we would make this more idiomatic: All supplied binaries go in a bin folder, this folder is added to the $PATH in the beginning of both script. A env var could be used to allow both nix and the user to prefer system binaries instead of those shipped with flash-multi.

Any feedback welcome :)

[benlye]

I've never heard of nix before but it looks neat. Happy to merge this as-is and improve it later :-)

[wucke13]

That is excellent news. Well, I can recommend you take a look at it, it many of todays problems in software distribution and dependency management. However, it does so at the cost of most innovative technologies, it's niche.