Like CWallet and CWalletDB, we will develop by making full use of inheritance.
wallet.dat: (CWallet, CWalletDB)
This method inherits the old way of managing private keys by units of 100 (elliptic curve cryptography).
wallethd.dat: (CWallethd, CWallethdDB)
This new way is to generate multiple private keys from the unique seed (elliptic curve cryptography).
walletq.dat: (CWalletq, CWalletqDB)
This method inherits the new way of managing private keys by units of 5 (Lamport signature).
