Add Documentation badge in README.rst

Courtesy of readthedocs.org
Unit test for unracked equipment in hwdoc views

Add a unit test for viewing an unracked equipment. This fails right now
due to a bug. refs #69, #71
Better locale and internationalization

Django 1.4 and above supports L10N and timezones. Add them to
settings.py.dist
Fix a bug with permissions in admin views

Turns out the order of the permission checking was wrong and a superuser
would not have full access. Fix this by reversing permission checking.
The regression was introduced in ce5292fe
Fix rendering of equipment without location info (fixes #69)