Added ProductListView with get_queryset to filter out inactive products. Updated catalog urls to use it.
Added ProductListViewTestCase to tests/views.py. Added import for test case in tests/__init__.py.
Merge pull request #260 from evandempsey/fixes

Created ProductListView to filter out inactive products.
Update documentation

How to avoid ImproperlyConfigured exceptions when extending the Product model

Signed-off-by: Martin Koistinen <mkoistinen@gmail.com>
Merge pull request #263 from mkoistinen/issue_160_documentation

Update documentation
Added structure for CheckoutSelectionViewTestCase.