The walletunlocker package contains the UnlockerService, which
implements the lnrpc.WalletUnlocker interface. This service is
used for receiving a password from the user over RPC, and doing
simple validity checks like making sure the user is not trying
to create a new wallet if one already exists, and that in case
the wallet exists, the provided password is correct.
The service will the pass the passwords over the CreatePasswords
or UnlockPasswords channels, for use within lnd.go.
