old_contents: '''plugin.py
  
  '''
  import ckan.plugins as plugins
  import ckan.plugins.toolkit as toolkit
  
  class AachenThemePlugin(plugins.SingletonPlugin):
      '''Theme for daten.aachen.de
  
      '''
      plugins.implements(plugins.IConfigurer)
  
      def update_config(self, config):
           toolkit.add_template_directory(config, 'templates')
  
new_contents: '''plugin.py
  
  '''
  import ckan.plugins as plugins
  import ckan.plugins.toolkit as toolkit
  
  class AachenThemePlugin(plugins.SingletonPlugin):
      '''Theme for daten.aachen.de
  
      '''
      plugins.implements(plugins.IConfigurer)
  
      def update_config(self, config):
           toolkit.add_template_directory(config, 'templates')
           toolkit.add_resource('fanstatic', 'aachen_theme')
  
subject: Add CSS. Untested!