[1.5.x] Add `form` to formwizard context (includes tests)

Backport of ba81164fb7 from master.

django/contrib/formtools/tests/wizard/wizardtests/tests.py

@@ -72,6 +72,10 @@ class WizardTests(object):
         self.assertEqual(response.context['wizard']['steps'].current, 'form2')
         self.assertEqual(response.context.get('another_var', None), True)
 
+        # ticket #19025: `form` should be included in context
+        form = response.context_data['wizard']['form']
+        self.assertEqual(response.context_data['form'], form)            
+
     def test_form_finish(self):
         response = self.client.get(self.wizard_url)
         self.assertEqual(response.status_code, 200)

django/contrib/formtools/wizard/views.py

@@ -530,7 +530,7 @@ class WizardView(TemplateView):
                         context.update({'another_var': True})
                     return context
         """
-        context = super(WizardView, self).get_context_data(**kwargs)
+        context = super(WizardView, self).get_context_data(form=form, **kwargs)
         context.update(self.storage.extra_data)
         context['wizard'] = {
             'form': form,