removed obsolte class AddPlaceholderFormMixin
Fixed typo
styling issues
djngError is the only so named directive, so why a priority?
djng-error is added only of Form does not derive from NgModelFormMixin
Added ChoiceFieldRenderer to reflect inheritance from Django widgets
Adopted inheritance from base widgets
Fixed: Radio Fields change into $dirty state, if one of them is clicked
Removed Django-Angular branding