Some people don't have all of them installed, so auto-detect them by looking at the available arches in /usr/libexec.
That way we can 'killall Sshuttle' and so on, and it looks right in the process list.
Just kidding. This is a squash of a whole bunch of unlabeled temporary commits that I produced over the last couple of weeks while writing a UI for MacOS while riding on airplanes and sitting in airports. So long, batch of useless commits!
