fixed problem with context processors

* 'WSGIRequest' object has no attribute 'session'
* ’WSGIRequest' object has no attribute ‘user’
I have a problem with my context processors. Because it use ``request.user`` and`` request.session``. If you do not wont accept this pull request, you can close and ignore this request. But I have a really problem with that. You can create new project (on dj1.4.13) with context processors and use processors with ``request.user`` for example and see couple errors with render ``table.as_html``. Because you are use ``standard_processors`` and extending it from ``settings.TEMPLATE_CONTEXT_PROCESSORS``.

    def something(request):
        return {'some_var': request.session.get('some_var')}