Add p() like in Ruby.

src/file.js

@@ -131,3 +131,7 @@ stdin.fd = File.STDIN_FILENO;
 this.puts = function (data, callback) {
   stdout.puts(data, callback);
 }
+
+this.p = function (data, callback) {
+  puts(JSON.stringify(data), callback);
+}

test/test_http.js

@@ -1,4 +1,4 @@
-puts(JSON.stringify({hello: "world"}));
+p({hello: "world"});
 new node.http.Server(function (msg) {
   setTimeout(function () {
     msg.sendHeader(200, [["Content-Type", "text/plain"]]);