Renamed grunt.js to Gruntfile.js.

Part of Grunt 0.4 upgrade. Issue #53.
Changed .jshintrc files for grunt-contrib-jshint.

Part of Grunt 0.4 upgrade. Issue #53.
Rewrote Grunt config file for Grunt version 0.4.

Part of Grunt 0.4 upgrade. Issue #53.
Added grunt-cli install command to travis config.

Part of Grunt 0.4 upgrade. Issue #53.
Updated grunt version and added new dependencies.

Part of Grunt 0.4 upgrade. Issue #53.