compatibility with Django 1.7: insert 'title' item

Insert function for SortedDict is deprecated in Django 1.5 and removed in Django 1.7 (https://github.com/django/django/commit/7379d9aceab01e007966b5fe1f47ba7590deb887). This commit contains workaround for that issue.

Unfortunately, the only way I have found is to copy the whole dictionary.