- read hex, base58, RFC1751, or passphrase
- derive Ed25519 keys from seed
- derive secp256k1 master key from seed
- encode keys to hex or base58
Note: at this time, the RFC1751 implementation is consistent with the
original spec but not consistent with rippled's RFC1751 implementation.
I don't know why rippled's RFC1751 implementation doesn't match the
spec. Maybe something to do with endianness.
