JS: Added a debug script I was using while developing local signing.

Handy to compare the server's serialization results with the client's. I figured
this might be useful whenever a local signing bug comes up, so it'd be good to
keep it around.

bin/debug_local_sign.js

@@ -0,0 +1,64 @@
+var ripple = require('../src/js');
+
+var v = {
+  seed: "snoPBrXtMeMyMHUVTgbuqAfg1SUTb",
+  addr: "rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh"
+};
+
+var remote = ripple.Remote.from_config({
+  "trusted" : true,
+  "websocket_ip" : "127.0.0.1",
+  "websocket_port" : 5006,
+  "websocket_ssl" : false,
+  "local_signing" : true
+});
+
+var tx_json = {
+	"Account" : v.addr,
+	"Amount" : "10000000",
+	"Destination" : "rEu2ULPiEQm1BAL8pYzmXnNX1aFX9sCks",
+	"Fee" : "10",
+	"Flags" : 0,
+	"Sequence" : 3,
+	"TransactionType" : "Payment"
+
+  //"SigningPubKey": '0396941B22791A448E5877A44CE98434DB217D6FB97D63F0DAD23BE49ED45173C9'
+};
+
+remote.on('connected', function () {
+  var req = remote.request_sign(v.seed, tx_json);
+  req.message.debug_signing = true;
+  req.on('success', function (result) {
+    console.log("SERVER RESULT");
+    console.log(result);
+
+    var sim = {};
+    var tx = remote.transaction();
+    tx.tx_json = tx_json;
+    tx._secret = v.seed;
+    tx.complete();
+    var unsigned = tx.serialize().to_hex();
+    tx.sign();
+
+    sim.tx_blob = tx.serialize().to_hex();
+    sim.tx_json = tx.tx_json;
+    sim.tx_signing_hash = tx.signing_hash().to_hex();
+    sim.tx_unsigned = unsigned;
+
+    console.log("\nLOCAL RESULT");
+    console.log(sim);
+
+    remote.connect(false);
+  });
+  req.on('error', function (err) {
+    if (err.error === "remoteError" && err.remote.error === "srcActNotFound") {
+      console.log("Please fund account "+v.addr+" to run this test.");
+    } else {
+      console.log('error', err);
+    }
+    remote.connect(false);
+  });
+  req.request();
+
+});
+remote.connect();