make errors stringifiable

app.js

+// make Errors stringifyable....
+if (!('toJSON' in Error.prototype))
+Object.defineProperty(Error.prototype, 'toJSON', {
+    value: function () {
+        var alt = {};
+
+        Object.getOwnPropertyNames(this).forEach(function (key) {
+            alt[key] = this[key];
+        }, this);
+
+        return alt;
+    },
+    configurable: true,
+    writable: true
+});
 
 function main() {
   var iarg = 2