title: django-cors-headers not work
body: <p>django-cors-headers not work</p>
  
  <pre><code>INSTALLED_APPS = (
      'django.contrib.admin',
      'django.contrib.auth',
      'django.contrib.contenttypes',
      'django.contrib.sessions',
      'django.contrib.messages',
      'django.contrib.staticfiles',
      'django.contrib.gis',
      'corsheaders',
      'rest_framework',
      'world',
      'userManager',
      'markPost',
      'BasicServices',
  )
  
  
  MIDDLEWARE_CLASSES = (
      'django.contrib.sessions.middleware.SessionMiddleware',
      'corsheaders.middleware.CorsMiddleware',
      'django.middleware.common.CommonMiddleware',
      'django.middleware.csrf.CsrfViewMiddleware',
      'django.contrib.auth.middleware.AuthenticationMiddleware',
      'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
      'django.contrib.messages.middleware.MessageMiddleware',
      'django.middleware.clickjacking.XFrameOptionsMiddleware',
  )
  
  CORS_ORIGIN_ALLOW_ALL = True
  CORS_ALLOW_CREDENTIALS = True
  </code></pre>
  
  <p>Everything is normal, but did not work</p>
  
  <p>here my response headers</p>
  
  <pre><code>Cache-Control: max-age=0
  Content-Type: text/html; charset=utf-8
  Date: Tue, 20 Jan 2015 13:16:17 GMT
  Expires: Tue, 20 Jan 2015 13:16:17 GMT
  Last-Modified: Tue, 20 Jan 2015 13:16:17 GMT
  Server: WSGIServer/0.1 Python/2.7.8
  Set-Cookie: csrftoken=snXksqpljbCLW0eZ0EElFxKbiUkYIvK0; expires=Tue, 19-Jan-2016 13:16:17 GMT; Max-Age=31449600; Path=/
  Vary: Cookie
  X-Frame-Options: SAMEORIGIN
  </code></pre>