Added auto-instantiators to classes

src/address.js

@@ -14,6 +14,7 @@ var p2sh_types = {
 };
 
 var Address = function (bytes, version) {
+    if (!(this instanceof Address)) { return new Address(bytes, version); }
     if (arguments[0] instanceof Address) {
         this.hash = arguments[0].hash;
         this.version = arguments[0].version;

src/transaction.js

@@ -9,6 +9,7 @@ var ECDSA = require('./ecdsa');
 var Address = require('./address');
 
 var Transaction = function (doc) {
+    if (!(this instanceof Transaction)) { return new Transaction(doc); }
     this.version = 1;
     this.lock_time = 0;
     this.ins = [];

src/wallet.js

@@ -15,6 +15,7 @@ var SecureRandom = require('./jsbn/rng');
 var rng = new SecureRandom();
 
 var Wallet = function (seed) {
+    if (!(this instanceof Wallet)) { return new Wallet(seed); }
 
     // Stored in a closure to make accidental serialization less likely
     var keys = [];