Avoid vim [sic!] dependency

I know this sounds crazy, but `xxd` is a weird tool, that is part of `vim`. It might be better to avoid it in favour of `sed`. I'm not sure, though.

    WARNINGS
           The tools weirdness matches its creators brain.
           Use entirely at your own risk.
           Copy files. Trace it. Become a wizard.
© `man xxd`