The code examples should now work correctly.
The `get_context_data` method in the examples was changed when
necessary to adopt a singular style (get context with super(...),
add the extra keys to the dict then return it).
Thanks to Remco Wendt for the initial report and to Tim Graham
for the review.
This also updates all dependent functionality, including modelform_factory
and modelformset_factory, and the generic views `ModelFormMixin`,
`CreateView` and `UpdateView` which gain a new `fields` attribute.
Credit goes to @SystemParadox. Originally developed at #DjangoCon Europe
but wasn't tested enough to merge in.
For history, please see https://github.com/pydanny/django/pull/4
