Grunt0.4.0rc5 compatibility

This makes the grunt-dustjs task compatible with 0.4.0rc5 of grunt by removing the missing `expandFiles` method.

Also renaming `grunt.js` to new `Gruntfile.js` name, adding jshint support for linting, and fixing some version numbers within the `package.js` file.

Bumped internal version to 0.2.1rc5