As an experiment, I imported django-guardian from the *.dsc files to git using git-dpm, and applied my changes. Not sure if I have got this right, it was the first time I used git-dpm.
The result is currently at: https://github.com/brianmay/django-guardian/tree/patched (patched branch). This is temporary only, as I am not the maintainer for this package. This fixes some of the easy Django 1.7 issues, however, I am still stuck on the CircularDependencyError mentioned above. At the moment, am wondering if maybe this is a Django 1.7 bug.