Alter CSRF exemption implementation

Test with released Django 1.7

The previous implementation of decorating `APIView.dispach` with the
`csrf_exempt` decorator allowed for an easy-to-make mistake where
someone could override the `dispatch` method on a view and inadvertantly
remove the csrf exemption of their api view.

By moving the decoration of the view into the `as_view` logic, it
becomes much more difficult to make this mistake.

Use explicit `many=True` in PaginationSerializer on `object_serializer` instantiation

Use explicit many=True for object_serializer instantiation in PaginationSerializer and add catch dummy 'many' kwarg on DefaultObjectSerializer

Correct testing documentation details.

Regression for #1810: Test login view renders

Restore body block to base template.

Fix #1804

Deprecate `.model` attribute on views

Browsable API cleanups. Fixes #1719

Update generic-views.md

Small grammar changes.