Version 2.2: Ubuntu 14.04, Django 1.7.1

Echoing the similar pull request in https://github.com/torchbox/vagrant-django-base/pull/2 …

- Ubuntu 14.04
- Django 1.7.1
- Postgres 9.3

Also python package version bumps:

- psycopg2 2.5.2 -> 2.5.4
- django-debug-toolbar 1.0.1 -> 1.2.2
- Pillow 2.0.0 -> 2.6.1
- fabric 1.8.1 -> 1.10.0
- gunicorn 18.0 -> 19.1.1
- removal of South

Also removal of some settings which were removed from the project defaults in 1.6 and 1.7.

Projects using this template will set up happily for me either building from the base ubuntu/trusty32 image or a pre-built vagrant-django-base v2.2 image.