Enhanced kwargs parameteres for FRFormField

see my issue :

https://github.com/django/django-localflavor/issues/101

label kwarg must not be fixed. In django.contrib.localflavor, we could change field label.

Actually, with 3 FRPhoneNumberField, three have 'PhoneNumber' in label...
Bug corrections

Fix bad syntax

I apologize for my first attempt.
Fix label FR form fields

labels are not configurable, there are harcoded
use setdefault instead of get on dict

update and correct all uses in fr/forms.py
Merge pull request #102 from submarcos/patch-1

Enhanced kwargs parameters for FRFormField