Security Stuff!

- modified the auth filter to return a 401 to synergize with our
angular interceptor
- added a csrf_json filter for extracting csrf_token from json payload
on routes that need it (like login)
- protected the books route with the 'auth' filter for demonstration of
what happens if your cookie expires etc…
- injected csrf token into angular using ng-init and a meta tag in the
layout file, this is available on every $scope 
- sends the csrf_token on on login