added res.json() function

README.md

 
 In the future, there will be middleware for POST request too.
 
+### Modifications to the request and response objects
+
+* `req.urlobj`: The result of `url.parse(req.url)`.
+* `res.json(object)`: A utility function to respond with JSON.
+
 ### webframe.static(root[, before])
 
 Serve static files.

index.js

 	return tpml;
 }
 
+function resJson(obj) {
+	res.writeHead(200, {
+		"content-type": "application/json"
+	});
+	this.end(JSON.stringify(obj));
+}
+
 class App {
 	constructor(options) {
 		options = options || {};
 
 		// Listen for requests
 		this.server.on("request", (req, res) => {
+			res.json = resJson;
 			var url = urllib.parse(req.url);
 			req.urlobj = url;
 

package.json

 {
   "name": "webframe",
-  "version": "0.1.4",
+  "version": "0.2.0",
   "description": "Web server.",
   "main": "index.js",
   "scripts": {