Allocate and init transaction store for newly created accounts.

acctmgr.go

@@ -285,7 +285,8 @@ func (am *AccountManager) CreateEncryptedWallet(passphrase []byte) error {
 	// manager.  Registering will fail if the new account can not be
 	// written immediately to disk.
 	a := &Account{
-		Wallet: wlt,
+		Wallet:  wlt,
+		TxStore: tx.NewStore(),
 	}
 	if err := am.RegisterNewAccount(a); err != nil {
 		return err

cmd.go

@@ -261,7 +261,9 @@ func (e *WalletOpenError) Error() string {
 func OpenSavedAccount(name string, cfg *config) (*Account, error) {
 	netdir := networkDir(cfg.Net())
 	if err := checkCreateDir(netdir); err != nil {
-		return nil, err
+		return nil, &WalletOpenError{
+			Err: err.Error(),
+		}
 	}
 
 	wlt := new(wallet.Wallet)