Fixed #23148 -- Minor tweaks in tutorial code samples

docs/intro/reusable-apps.txt

@@ -66,6 +66,9 @@ After the previous tutorials, our project should look like this::
         polls/
             __init__.py
             admin.py
+            migrations/
+                __init__.py
+                0001_initial.py
             models.py
             static/
                 polls/

docs/intro/tutorial01.txt

@@ -704,8 +704,11 @@ demonstration:
     :filename: polls/models.py
 
     import datetime
+
+    from django.db import models
     from django.utils import timezone
-    # ...
+
+
     class Question(models.Model):
         # ...
         def was_published_recently(self):

docs/intro/tutorial02.txt

@@ -275,8 +275,8 @@ with the admin just as we did with ``Question``. That's easy:
     :filename: polls/admin.py
 
     from django.contrib import admin
-    from polls.models import Choice
-
+    from polls.models import Choice, Question
+    # ...
     admin.site.register(Choice)
 
 Now "Choices" is an available option in the Django admin. The "Add choice" form
@@ -319,8 +319,7 @@ registration code to read:
     class QuestionAdmin(admin.ModelAdmin):
         fieldsets = [
             (None,               {'fields': ['question_text']}),
-            ('Date information', {'fields': ['pub_date'],
-                                  'classes': ['collapse']}),
+            ('Date information', {'fields': ['pub_date'], 'classes': ['collapse']}),
         ]
         inlines = [ChoiceInline]
 

docs/intro/tutorial03.txt

@@ -97,7 +97,7 @@ In the ``polls/urls.py`` file include the following code:
     from polls import views
 
     urlpatterns = [
-        url(r'^$', views.index, name='index')
+        url(r'^$', views.index, name='index'),
     ]
 
 The next step is to point the root URLconf at the ``polls.urls`` module. In
@@ -466,7 +466,7 @@ provides a shortcut. Here's the ``detail()`` view, rewritten:
 .. snippet::
     :filename: polls/views.py
 
-    from django.shortcuts import render, get_object_or_404
+    from django.shortcuts import get_object_or_404, render
 
     from polls.models import Question
     # ...

docs/intro/tutorial04.txt

@@ -72,6 +72,7 @@ create a real version. Add the following to ``polls/views.py``:
     from django.shortcuts import get_object_or_404, render
     from django.http import HttpResponseRedirect, HttpResponse
     from django.core.urlresolvers import reverse
+
     from polls.models import Choice, Question
     # ...
     def vote(request, question_id):