Ajustments on generation

Hi Loic,

I was testing your scaffold bundle and I had to do some ajustments to match the current documentation and to make sure that the created forms were right on the screen, so I did a few changes.

* add *span16* class on forms (create and edit), both blade and php versions
* changed controller to extend *Base_Controller*, due to documentation recommendation http://laravel.com/docs/controllers#the-basics