status: Switch error to panic for statusValueToValue().

This is an error case that should be impossible. Panic for it, instead
of handling the error.
spark: Stop creating new tokens so freely.

If we don't have a token, or our token is invalid, try looking one
up instead of creating a new one. Only create if we can't look one
up.

Also, stop storing tokens in the config file. Just look them up at
startup instead.