Modified UserObjectsOnlyAuthorization to check auth for update actions
Add django REST framework

This package seems to be more flexible, better documented and is more
actively developed.
Add support for token authentication to REST API
Add missing endpoints, set some to read only, cleanup querysets
Remove basic authentication from default list
Set the license author when saving exercises or their images
Fix some pep8 formatting errors
Add object level permissions for creation operations
Remove first attempt at RW access for old api/v1

Since it looks we're going forward with Rest Framework, the v1 api will
remain read-only and this is won't be needed
Fix pep8 formatting errors
Make the canonical representation of workouts accessible through the API
Require authentication for accessing private endpoints
Fix the queryset, this is the endpoint for Sets not Settings
Expose the nutritional values of meals through the API
Add live browsing view for the new API

This is basically the form used by the Django REST Framework, with some
things tweaked to fit into the application design.
Also output the URL of the original exercise image file
Allow ordering of endpoints

For this to work, it is necessary that the ViewSets have either a
'ordering_fields' or a 'serializer_class' attribute
Add filtering of endpoints

This needed an external django app, 'django-filter'
Update and refactor the testcase for the REST API

Since the API now supports write operations, the testcases test
performing DELETE, POST, PATCH and PUT operations

--HG--
rename : wger/config/tests/test_language.py => wger/core/tests/test_language.py
Fix active tab when browsing the api