Made it useful for scripts

Hey Chris,

Not sure if this interests you but I made this tool a bit more useful:

1. It always exits one way or another.
2. Added exit codes that let a caller tell what happened (good or bad).
3. Only output data from subs/methods (we could add a `--debug` flag too I guess)

Basically makes it useful to use from larger scripts that want to grab data from somewhere.