Batch mode enhancements

- Multiple passphrases as arguments or from file (-f)
- Filter by min/max passphrase length (--min-length, max-length)
- Filter by candidate bitcoin addresses file (-c/--candidates-file)
- Expand provided passphrases by cartesian product/permutation/combination
   (--expander, -n)
- NB Output now in the format "<passphrase> <address> <private key>