Enable the database.

* Add sqlite config to base settings.
* Update tests to use Django's database aware TestCase.
* Install south.
* Install django-waffle.
* Update jenkins to use the database for CI.

Django admin will be enabled in a separate PR.
Merge remote branch 'pmac/enable-database' into demo3b

Conflicts:
	lib/l10n_utils/tests/test_dotlang.py
Merge branch 'bug-870998-firefoxos-type' into demo3b