First pass at integrating a Markdown parser

Internal links don't work yet.

@natecain - have I included the node module in the right way?

plugins/tiddlywiki/markdown/files/tiddlywiki.files

@@ -0,0 +1,12 @@
+{
+	"tiddlers": [
+		{
+			"file": "../../../../node_modules/markdown/lib/markdown.js",
+			"fields": {
+				"type": "application/javascript",
+				"title": "$:/plugins/tiddlywiki/markdown/markdown.js",
+				"module-type": "library"
+			}
+		}
+	]
+}

plugins/tiddlywiki/markdown/plugin.info

@@ -0,0 +1,6 @@
+{
+	"title": "$:/plugins/tiddlywiki/markdown",
+	"description": "Markdown plugin wrapping markdown-js",
+	"author": "JeremyRuston",
+	"coreVersion": ">=5.0.0"
+}

plugins/tiddlywiki/markdown/wrapper.js

@@ -0,0 +1,60 @@
+/*\
+title: $:/plugins/tiddlywiki/markdown/wrapper.js
+type: application/javascript
+module-type: parser
+
+Wraps up the markdown-js parser for use in TiddlyWiki5
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+var markdown = require("$:/plugins/tiddlywiki/markdown/markdown.js");
+
+function transformNodes(nodes) {
+	var results = [];
+	for(var index=0; index<nodes.length; index++) {
+		results.push(transformNode(nodes[index]));
+	}
+	return results;
+}
+
+function transformNode(node) {
+	if($tw.utils.isArray(node)) {
+		var p = 0,
+			widget = {type: "element", tag: node[p++]};
+		if(!$tw.utils.isArray(node[p]) && typeof(node[p]) === "object") {
+			widget.attributes = {};
+			$tw.utils.each(node[p++],function(value,name) {
+				widget.attributes[name] = {type: "string", value: value};
+			});
+		}
+		widget.children = transformNodes(node.slice(p++));
+		return widget;
+	} else {
+		return {type: "text", text: node};
+	}
+}
+
+var MarkdownParser = function(type,text,options) {
+	var markdownTree = markdown.toHTMLTree(text);
+	this.tree = transformNodes(markdownTree.slice(1));
+};
+
+/*
+
+[ 'html',
+  [ 'p', 'something' ],
+  [ 'h1',
+    'heading and ',
+    [ 'strong', 'other' ] ] ]
+
+*/
+
+exports["text/x-markdown"] = MarkdownParser;
+
+})();
+