upgrade to django 1.7

Removes south and south migrations in favor of django migrations.
To upgrade your deployed application run `python manage.py migrate
--fake builds` after you have installed django 1.7.
Merge pull request #17 from tind/dev-pxke

 Add hint to the login form

Clean the way the command is executed for non-darwin platform

Fix form error management
add waffle.io badge
Merge pull request #19 from waffle-iron/master

waffle.io Badge
Merge pull request #12 from relekang/django-1.7

upgrade to django 1.7
Create LICENCE
run coverage
Merge pull request #20 from tind/coverage

run coverage
Unshadow exception, regroupe default .frigg.yml at one place
test