Added bower, component, grunt and composer support

* Editor style CSS
* No more language selector CSS. You can use your own
* Header and footer scripts called by component.json (you still can use
old ones on header-scripts and footer-scripts)
* functions.php now use autoload and a Theme class;
* Now we have a .gitignore!
* WordPress coding style corrections;
* index.html for component.json. Test it!