Add django-rest-framework and users endpoint
Switch to ViewSets
Add votes endpoint
Add posts endpoint
Add write functionality to votes endpoint
Refactor vote validation method

And make it work with AJAX code (from HTML pages) and API code (from the RESTful webservice).
Refactor vote validation using proper validation methods in the serializer
Post endpoint validation in place, but still dirty code
Post endpoint completed
Merge branch 'api' into develop