Build (with Node.js/Grunt)

Use Node.js/Grunt to build release package including minification of CSS & JS and automatic linting.
//todo: write simple docs. Think up other build tasks that should be done. 
-- output like this:
Running "clean:build" (clean) task
Cleaning build/...OK

Running "copy:main" (copy) task
Copied 9 files

Running "jshint:src" (jshint) task
>> 1 file lint free.

Running "uglify:build" (uglify) task
File build/js/so_tag.min.js created: 11.24 kB → 3.36 kB

Running "cssmin:minify" (cssmin) task
File build/css/simple_blue.min.css created: 1.5 kB → 1.2 kB
File build/css/so_tag.min.css created: 1.47 kB → 1.16 kB

Done, without errors.