Update for PSR-4

You can now update the directories for better readability.
Everything in FormTranslationBundle folder can go directly in form-translation-bundle.

And more readable if you put folders : 
 - Builders
 - DependencyInjection
 - Form
 - Model
 - Resources 

in src folder
If you do that, update your autoload : `"Elao\\Bundle\\FormTranslationBundle": "src/"`