grunt 0.4 supported

[Grunt 0.4.0 Released  at February 18, 2013.](http://gruntjs.com/blog/2013-02-18-grunt-0.4.0-released)

Just follow:

```bash
$ npm uninstall -g grunt
$ npm install -g grunt-cli
$ grunt somtTasks
```

And this PR make the 0.4.0-supported Gruntfile.