Update csrf value to use value if present in context, then fall back to cookie.

Updated database samples.
Added migrations for sample project models.
Updated Category model to make order not editable.

adminsortable/templates/adminsortable/csrf/jquery.django-csrf.html

@@ -16,7 +16,7 @@
         return cookieValue;
     }
 
-    var csrftoken = getCookie('{{ csrf_cookie_name }}');
+    var csrftoken = '{{ csrf_token }}' || getCookie('{{ csrf_cookie_name }}');
 
     function csrfSafeMethod(method) {
         // these HTTP methods do not require CSRF protection