Make adn-authorization work

 - If there is no access_token in the config:
     - Start a small http-server on localhost:8000
     - Request authorization with adn and wait for the redirect on localhost:8000
     - On a simple get for '/' return a simple page with javascript to extract the access_token from the anchor
     - Get localhost again with the access_token as GET-parameter
     - Save the access_token in the config
 - Use the access_token from the config for api-authentication