Deprecate s3.py backend
I feel like I brought this up before, but maybe I didn't.
backends/s3.py should be deprecated in favor of backends/s3boto.py
s3.py is based off an Amazon script that is unmaintained and mostly unused (except here). This wouldn't be such a problem, except that commits that could be done on boto to improve everybody's Python experience are being done in the silo of s3.py, like this: http://code.welldev.org/django-storages/changeset/41cc5987a7fb/