Add "use strict" to most core nodes.

(skipping ones that may have other work in progress)

nodes/core/parsers/70-CSV.js

@@ -15,6 +15,7 @@
  **/
 
 module.exports = function(RED) {
+    "use strict";
     function CSVNode(n) {
         RED.nodes.createNode(this,n);
         this.template = n.temp.split(",");

nodes/core/parsers/70-JSON.js

@@ -15,8 +15,9 @@
  **/
 
 module.exports = function(RED) {
+    "use strict";
     var util = require("util");
-    
+
     function JSONNode(n) {
         RED.nodes.createNode(this,n);
         var node = this;

nodes/core/parsers/70-XML.js

@@ -15,10 +15,11 @@
  **/
 
 module.exports = function(RED) {
+    "use strict";
     var xml2js = require('xml2js');
     var parseString = xml2js.parseString;
     var builder = new xml2js.Builder({renderOpts:{pretty:false}});
-    
+
     function XMLNode(n) {
         RED.nodes.createNode(this,n);
         var node = this;