UPGRADE FROM 2.0 to 2.1

Form

Due to refactoring in the Form Component, some type definitions have been changed and new ones have been introduced:
- sonata_type_model : this type now only renders a standard select widget or a list widget (if the multiple option is set)
- sonata_type_model_list : this type replaces the option edit = list provided as a 4th argument on the sonata_type_model