Add CLI option to pass Electrod executable as an argument

[grayswandyr]

Would allow testing several versions of Electrod.

[nmacedo]

You can change the static library path with java -Djava.library.path= ..., would that be enough?

[grayswandyr]

Hmm if it also works with binaries (like electrod) and not only plain libraires, I can live with that yes.