Fix wallet.js so it does not crash with HDWallet.

src/wallet.js

@@ -5,11 +5,10 @@ var util = require('./util');
 
 var BigInteger = require('./jsbn/jsbn');
 
-var BIP32key = require('./bip32');
-
 var Transaction = require('./transaction').Transaction;
 var TransactionIn = require('./transaction').TransactionIn;
 var TransactionOut = require('./transaction').TransactionOut;
+var HDWallet = require('./hdwallet.js')
 
 var SecureRandom = require('./jsbn/rng');
 var rng = new SecureRandom();
@@ -34,7 +33,7 @@ var Wallet = function (seed) {
             rng.nextBytes(seedBytes);
             seed = conv.bytesToString(seedBytes)
         }
-        masterkey = new BIP32key(seed);
+        masterkey = new HDWallet(seed);
         keys = []
     }
     this.newMasterKey(seed)