Add missing imports to the examples in the 'First Steps'

docs/intro/overview.txt

@@ -24,6 +24,8 @@ representing your models -- so far, it's been solving two years' worth of
 database-schema problems. Here's a quick example, which might be saved in
 the file ``mysite/news/models.py``::
 
+    from django.db import models 
+
     class Reporter(models.Model):
         full_name = models.CharField(max_length=70)
 
@@ -214,6 +216,8 @@ Generally, a view retrieves data according to the parameters, loads a template
 and renders the template with the retrieved data. Here's an example view for
 ``year_archive`` from above::
 
+    from django.shortcuts import render_to_response 
+
     def year_archive(request, year):
         a_list = Article.objects.filter(pub_date__year=year)
         return render_to_response('news/year_archive.html', {'year': year, 'article_list': a_list})

docs/intro/tutorial01.txt

@@ -582,6 +582,8 @@ of this object. Let's fix that by editing the polls model (in the
 ``Choice``. On Python 3, simply replace ``__unicode__`` by ``__str__`` in the
 following example::
 
+    from django.db import models
+
     class Poll(models.Model):
         # ...
         def __unicode__(self):  # Python 3: def __str__(self):

docs/intro/tutorial02.txt

@@ -158,6 +158,9 @@ you want when you register the object.
 Let's see how this works by re-ordering the fields on the edit form. Replace
 the ``admin.site.register(Poll)`` line with::
 
+    from django.contrib import admin
+    from polls.models import Poll
+
     class PollAdmin(admin.ModelAdmin):
         fields = ['pub_date', 'question']
 
@@ -179,6 +182,9 @@ of fields, choosing an intuitive order is an important usability detail.
 And speaking of forms with dozens of fields, you might want to split the form
 up into fieldsets::
 
+    from django.contrib import admin
+    from polls.models import Poll
+
     class PollAdmin(admin.ModelAdmin):
         fieldsets = [
             (None,               {'fields': ['question']}),
@@ -198,6 +204,9 @@ You can assign arbitrary HTML classes to each fieldset. Django provides a
 This is useful when you have a long form that contains a number of fields that
 aren't commonly used::
 
+        from django.contrib import admin
+        from polls.models import Poll
+
         class PollAdmin(admin.ModelAdmin):
             fieldsets = [
                 (None,               {'fields': ['question']}),
@@ -218,6 +227,7 @@ Yet.
 There are two ways to solve this problem. The first is to register ``Choice``
 with the admin just as we did with ``Poll``. That's easy::
 
+    from django.contrib import admin
     from polls.models import Choice
 
     admin.site.register(Choice)
@@ -342,6 +352,12 @@ representation of the output.
 You can improve that by giving that method (in :file:`polls/models.py`) a few
 attributes, as follows::
 
+    import datetime
+    from django.utils import timezone
+    from django.db import models
+
+    from polls.models import Poll
+
     class Poll(models.Model):
         # ...
         def was_published_recently(self):

docs/intro/tutorial03.txt

@@ -393,6 +393,9 @@ Now, let's tackle the poll detail view -- the page that displays the question
 for a given poll. Here's the view::
 
     from django.http import Http404
+    from django.shortcuts import render
+
+    from polls.models import Poll
     # ...
     def detail(request, poll_id):
         try:
@@ -420,6 +423,8 @@ and raise :exc:`~django.http.Http404` if the object doesn't exist. Django
 provides a shortcut. Here's the ``detail()`` view, rewritten::
 
     from django.shortcuts import render, get_object_or_404
+
+    from polls.models import Poll
     # ...
     def detail(request, poll_id):
         poll = get_object_or_404(Poll, pk=poll_id)

docs/intro/tutorial04.txt

@@ -136,6 +136,8 @@ object. For more on :class:`~django.http.HttpRequest` objects, see the
 After somebody votes in a poll, the ``vote()`` view redirects to the results
 page for the poll. Let's write that view::
 
+    from django.shortcuts import get_object_or_404, render
+
     def results(request, poll_id):
         poll = get_object_or_404(Poll, pk=poll_id)
         return render(request, 'polls/results.html', {'poll': poll})