nixed

Create derivation for a [Nix package manager](http://nixos.org/nix/).

If you have nix installed, you can just do `nix-build` (to just locally build) or `nix-env -i mpdas -f default.nix` (to install as user).

 P.S. Going to submit your program to official repo of `nixpkgs`, when you release 0.4 :)