Move node-webkit saver into a plugin

We don’t need it for TiddlyDesktop now that it reuses the TiddlyFox
saver. But it is still useful for embedding a TW directly into a
node-webkit app

plugins/tiddlywiki/nodewebkitsaver/nodewebkit.js

@@ -0,0 +1,61 @@
+/*\
+title: $:/core/modules/savers/nodewebkit.js
+type: application/javascript
+module-type: saver
+
+Handles saving changes in the node-webkit environment. Not required by TiddlyDesktop, which re-uses the TiddlyFox saver, but useful if you're embedding a single TiddlyWiki document into a node-webkit app.
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false, netscape: false, Components: false */
+"use strict";
+
+var NodeWebKitSaver = function(wiki) {
+};
+
+NodeWebKitSaver.prototype.save = function(text,method,callback) {
+	// Bail out unless this is a save (rather than a download)
+	if(method !== "save") {
+		return false;
+	}
+	// Get the pathname of this document
+	var pathname = document.location.pathname;
+	// Test for a Windows path of the form /x:/blah/blah
+	if(/^\/[A-Z]\:\//i.test(pathname)) {
+		// Remove the leading slash
+		pathname = pathname.substr(1);
+		// Convert slashes to backslashes
+		pathname = pathname.replace(/\//g,"\\");
+	}
+	// Try to save
+	var fs = require("fs");
+	fs.writeFile(pathname,text,callback);
+	return true;
+};
+
+/*
+Information about this saver
+*/
+NodeWebKitSaver.prototype.info = {
+	name: "nodewebkit",
+	priority: 1700
+};
+
+/*
+Static method that returns true if this saver is capable of working
+*/
+exports.canSave = function(wiki) {
+	// Check if we're running under node-webkit
+	return (typeof process == "object")
+};
+
+/*
+Create an instance of this saver
+*/
+exports.create = function(wiki) {
+	return new NodeWebKitSaver(wiki);
+};
+
+})();

plugins/tiddlywiki/nodewebkitsaver/plugin.info

@@ -0,0 +1,6 @@
+{
+	"title": "$:/plugins/tiddlywiki/nodewebkitsaver",
+	"description": "Native saving for node-webkit",
+	"author": "JeremyRuston",
+	"core-version": ">=5.0.0"
+}