Add support for macro modules

Now JavaScript macros can be defined in "macro" modules

core/modules/macros/version.js

@@ -0,0 +1,30 @@
+/*\
+title: $:/core/modules/macros/version.js
+type: application/javascript
+module-type: macro
+
+Macro to return the TiddlyWiki core version number
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+/*
+Information about this macro
+*/
+
+exports.name = "version";
+
+exports.params = [];
+
+/*
+Run the macro
+*/
+exports.run = function() {
+	return $tw.version;
+};
+
+})();