diff --git a/django/contrib/admin/forms.py b/django/contrib/admin/forms.py
index e790e2e3b6..4e828697e8 100644
--- a/django/contrib/admin/forms.py
+++ b/django/contrib/admin/forms.py
@@ -9,6 +9,7 @@ from django.utils.translation import ugettext_lazy, ugettext as _
 ERROR_MESSAGE = ugettext_lazy("Please enter the correct username and password "
         "for a staff account. Note that both fields are case-sensitive.")
 
+
 class AdminAuthenticationForm(AuthenticationForm):
     """
     A custom authentication form used in the admin app.
diff --git a/django/contrib/admin/sites.py b/django/contrib/admin/sites.py
index 4bb6440877..e57eafe256 100644
--- a/django/contrib/admin/sites.py
+++ b/django/contrib/admin/sites.py
@@ -2,7 +2,7 @@ from functools import update_wrapper
 from django.http import Http404, HttpResponseRedirect
 from django.contrib.admin import ModelAdmin, actions
 from django.contrib.admin.forms import AdminAuthenticationForm
-from django.contrib.auth import REDIRECT_FIELD_NAME
+from django.contrib.auth import REDIRECT_FIELD_NAME, get_user_model
 from django.contrib.contenttypes import views as contenttype_views
 from django.views.decorators.csrf import csrf_protect
 from django.db.models.base import ModelBase
@@ -79,20 +79,23 @@ class AdminSite(object):
             if model in self._registry:
                 raise AlreadyRegistered('The model %s is already registered' % model.__name__)
 
-            # If we got **options then dynamically construct a subclass of
-            # admin_class with those **options.
-            if options:
-                # For reasons I don't quite understand, without a __module__
-                # the created class appears to "live" in the wrong place,
-                # which causes issues later on.
-                options['__module__'] = __name__
-                admin_class = type("%sAdmin" % model.__name__, (admin_class,), options)
+            # Ignore the registration if the model has been
+            # swapped out.
+            if not model._meta.swapped:
+                # If we got **options then dynamically construct a subclass of
+                # admin_class with those **options.
+                if options:
+                    # For reasons I don't quite understand, without a __module__
+                    # the created class appears to "live" in the wrong place,
+                    # which causes issues later on.
+                    options['__module__'] = __name__
+                    admin_class = type("%sAdmin" % model.__name__, (admin_class,), options)
 
-            # Validate (which might be a no-op)
-            validate(admin_class, model)
+                # Validate (which might be a no-op)
+                validate(admin_class, model)
 
-            # Instantiate the admin class to save in the registry
-            self._registry[model] = admin_class(model, self)
+                # Instantiate the admin class to save in the registry
+                self._registry[model] = admin_class(model, self)
 
     def unregister(self, model_or_iterable):
         """
@@ -317,6 +320,7 @@ class AdminSite(object):
             REDIRECT_FIELD_NAME: request.get_full_path(),
         }
         context.update(extra_context or {})
+
         defaults = {
             'extra_context': context,
             'current_app': self.name,
diff --git a/django/contrib/admin/templates/admin/base.html b/django/contrib/admin/templates/admin/base.html
index caa26744d4..3d2a07eba2 100644
--- a/django/contrib/admin/templates/admin/base.html
+++ b/django/contrib/admin/templates/admin/base.html
@@ -26,7 +26,7 @@
         {% if user.is_active and user.is_staff %}
         <div id="user-tools">
             {% trans 'Welcome,' %}
-            <strong>{% filter force_escape %}{% firstof user.first_name user.username %}{% endfilter %}</strong>.
+            <strong>{% filter force_escape %}{% firstof user.get_short_name user.username %}{% endfilter %}</strong>.
             {% block userlinks %}
                 {% url 'django-admindocs-docroot' as docsroot %}
                 {% if docsroot %}
diff --git a/django/contrib/auth/__init__.py b/django/contrib/auth/__init__.py
index 0b3ccf7d8c..d5d4430dc0 100644
--- a/django/contrib/auth/__init__.py
+++ b/django/contrib/auth/__init__.py
@@ -6,9 +6,10 @@ SESSION_KEY = '_auth_user_id'
 BACKEND_SESSION_KEY = '_auth_user_backend'
 REDIRECT_FIELD_NAME = 'next'
 
+
 def load_backend(path):
     i = path.rfind('.')
-    module, attr = path[:i], path[i+1:]
+    module, attr = path[:i], path[i + 1:]
     try:
         mod = import_module(module)
     except ImportError as e:
@@ -21,6 +22,7 @@ def load_backend(path):
         raise ImproperlyConfigured('Module "%s" does not define a "%s" authentication backend' % (module, attr))
     return cls()
 
+
 def get_backends():
     from django.conf import settings
     backends = []
@@ -30,6 +32,7 @@ def get_backends():
         raise ImproperlyConfigured('No authentication backends have been defined. Does AUTHENTICATION_BACKENDS contain anything?')
     return backends
 
+
 def authenticate(**credentials):
     """
     If the given credentials are valid, return a User object.
@@ -46,6 +49,7 @@ def authenticate(**credentials):
         user.backend = "%s.%s" % (backend.__module__, backend.__class__.__name__)
         return user
 
+
 def login(request, user):
     """
     Persist a user id and a backend in the request. This way a user doesn't
@@ -69,6 +73,7 @@ def login(request, user):
         request.user = user
     user_logged_in.send(sender=user.__class__, request=request, user=user)
 
+
 def logout(request):
     """
     Removes the authenticated user's ID from the request and flushes their
@@ -86,6 +91,16 @@ def logout(request):
         from django.contrib.auth.models import AnonymousUser
         request.user = AnonymousUser()
 
+
+def get_user_model():
+    "Return the User model that is active in this project"
+    from django.conf import settings
+    from django.db.models import get_model
+
+    app_label, model_name = settings.AUTH_USER_MODEL.split('.')
+    return get_model(app_label, model_name)
+
+
 def get_user(request):
     from django.contrib.auth.models import AnonymousUser
     try:
diff --git a/django/contrib/auth/backends.py b/django/contrib/auth/backends.py
index 04fbef4788..da4c9c727a 100644
--- a/django/contrib/auth/backends.py
+++ b/django/contrib/auth/backends.py
@@ -1,4 +1,5 @@
-from django.contrib.auth.models import User, Permission
+from django.contrib.auth import get_user_model
+from django.contrib.auth.models import Permission
 
 
 class ModelBackend(object):
@@ -10,10 +11,13 @@ class ModelBackend(object):
     # configurable.
     def authenticate(self, username=None, password=None):
         try:
-            user = User.objects.get(username=username)
+            UserModel = get_user_model()
+            user = UserModel.objects.get(**{
+                getattr(UserModel, 'USERNAME_FIELD', 'username'): username
+            })
             if user.check_password(password):
                 return user
-        except User.DoesNotExist:
+        except UserModel.DoesNotExist:
             return None
 
     def get_group_permissions(self, user_obj, obj=None):
@@ -58,8 +62,9 @@ class ModelBackend(object):
 
     def get_user(self, user_id):
         try:
-            return User.objects.get(pk=user_id)
-        except User.DoesNotExist:
+            UserModel = get_user_model()
+            return UserModel.objects.get(pk=user_id)
+        except UserModel.DoesNotExist:
             return None
 
 
@@ -92,17 +97,23 @@ class RemoteUserBackend(ModelBackend):
         user = None
         username = self.clean_username(remote_user)
 
+        UserModel = get_user_model()
+
         # Note that this could be accomplished in one try-except clause, but
         # instead we use get_or_create when creating unknown users since it has
         # built-in safeguards for multiple threads.
         if self.create_unknown_user:
-            user, created = User.objects.get_or_create(username=username)
+            user, created = UserModel.objects.get_or_create(**{
+                getattr(UserModel, 'USERNAME_FIELD', 'username'): username
+            })
             if created:
                 user = self.configure_user(user)
         else:
             try:
-                user = User.objects.get(username=username)
-            except User.DoesNotExist:
+                user = UserModel.objects.get(**{
+                    getattr(UserModel, 'USERNAME_FIELD', 'username'): username
+                })
+            except UserModel.DoesNotExist:
                 pass
         return user
 
diff --git a/django/contrib/auth/management/__init__.py b/django/contrib/auth/management/__init__.py
index 8287c97d58..2ae4084416 100644
--- a/django/contrib/auth/management/__init__.py
+++ b/django/contrib/auth/management/__init__.py
@@ -5,10 +5,9 @@ import getpass
 import locale
 import unicodedata
 
-from django.contrib.auth import models as auth_app
+from django.contrib.auth import models as auth_app, get_user_model
 from django.core import exceptions
 from django.db.models import get_models, signals
-from django.contrib.auth.models import User, get_user_model
 
 
 def _get_permission_codename(action, opts):
@@ -106,7 +105,7 @@ def get_default_username(check_db=True):
     """
     # If the User model has been swapped out, we can't make any assumptions
     # about the default user name.
-    if User._meta.swapped:
+    if auth_app.User._meta.swapped:
         return ''
 
     default_username = get_system_username()
@@ -118,15 +117,15 @@ def get_default_username(check_db=True):
 
     # Run the username validator
     try:
-        User._meta.get_field('username').run_validators(default_username)
+        auth_app.User._meta.get_field('username').run_validators(default_username)
     except exceptions.ValidationError:
         return ''
 
     # Don't return the default username if it is already taken.
     if check_db and default_username:
         try:
-            User.objects.get(username=default_username)
-        except User.DoesNotExist:
+            auth_app.User.objects.get(username=default_username)
+        except auth_app.User.DoesNotExist:
             pass
         else:
             return ''
diff --git a/django/contrib/auth/management/commands/changepassword.py b/django/contrib/auth/management/commands/changepassword.py
index 2a8a19e6cb..1a2387442c 100644
--- a/django/contrib/auth/management/commands/changepassword.py
+++ b/django/contrib/auth/management/commands/changepassword.py
@@ -1,8 +1,8 @@
 import getpass
 from optparse import make_option
 
+from django.contrib.auth import get_user_model
 from django.core.management.base import BaseCommand, CommandError
-from django.contrib.auth.models import get_user_model
 from django.db import DEFAULT_DB_ALIAS
 
 
diff --git a/django/contrib/auth/management/commands/createsuperuser.py b/django/contrib/auth/management/commands/createsuperuser.py
index ffe248753a..3db1b877e1 100644
--- a/django/contrib/auth/management/commands/createsuperuser.py
+++ b/django/contrib/auth/management/commands/createsuperuser.py
@@ -6,8 +6,8 @@ import getpass
 import sys
 from optparse import make_option
 
+from django.contrib.auth import get_user_model
 from django.contrib.auth.management import get_default_username
-from django.contrib.auth.models import get_user_model
 from django.core import exceptions
 from django.core.management.base import BaseCommand, CommandError
 from django.db import DEFAULT_DB_ALIAS
diff --git a/django/contrib/auth/models.py b/django/contrib/auth/models.py
index 62bf68afbc..6604423512 100644
--- a/django/contrib/auth/models.py
+++ b/django/contrib/auth/models.py
@@ -1,7 +1,6 @@
 import re
 import urllib
 
-from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 from django.core.mail import send_mail
 from django.core import validators
@@ -271,12 +270,6 @@ class AbstractBaseUser(models.Model):
         raise NotImplementedError()
 
 
-def get_user_model():
-    "Return the User model that is active in this project"
-    app_label, model_name = settings.AUTH_USER_MODEL.split('.')
-    return models.get_model(app_label, model_name)
-
-
 class User(AbstractBaseUser):
     """
     Users within the Django authentication system are represented by this
diff --git a/django/contrib/auth/views.py b/django/contrib/auth/views.py
index c86ef53595..d32d2180b9 100644
--- a/django/contrib/auth/views.py
+++ b/django/contrib/auth/views.py
@@ -70,6 +70,7 @@ def login(request, template_name='registration/login.html',
     return TemplateResponse(request, template_name, context,
                             current_app=current_app)
 
+
 def logout(request, next_page=None,
            template_name='registration/logged_out.html',
            redirect_field_name=REDIRECT_FIELD_NAME,
@@ -100,6 +101,7 @@ def logout(request, next_page=None,
         # Redirect to this page until the session has been cleared.
         return HttpResponseRedirect(next_page or request.path)
 
+
 def logout_then_login(request, login_url=None, current_app=None, extra_context=None):
     """
     Logs out the user if he is logged in. Then redirects to the log-in page.
@@ -108,6 +110,7 @@ def logout_then_login(request, login_url=None, current_app=None, extra_context=N
         login_url = settings.LOGIN_URL
     return logout(request, login_url, current_app=current_app, extra_context=extra_context)
 
+
 def redirect_to_login(next, login_url=None,
                       redirect_field_name=REDIRECT_FIELD_NAME):
     """
@@ -124,6 +127,7 @@ def redirect_to_login(next, login_url=None,
 
     return HttpResponseRedirect(urlparse.urlunparse(login_url_parts))
 
+
 # 4 views for password reset:
 # - password_reset sends the mail
 # - password_reset_done shows a success message for the above
@@ -169,6 +173,7 @@ def password_reset(request, is_admin_site=False,
     return TemplateResponse(request, template_name, context,
                             current_app=current_app)
 
+
 def password_reset_done(request,
                         template_name='registration/password_reset_done.html',
                         current_app=None, extra_context=None):
@@ -178,6 +183,7 @@ def password_reset_done(request,
     return TemplateResponse(request, template_name, context,
                             current_app=current_app)
 
+
 # Doesn't need csrf_protect since no-one can guess the URL
 @sensitive_post_parameters()
 @never_cache
@@ -191,7 +197,7 @@ def password_reset_confirm(request, uidb36=None, token=None,
     View that checks the hash in a password reset link and presents a
     form for entering a new password.
     """
-    assert uidb36 is not None and token is not None # checked by URLconf
+    assert uidb36 is not None and token is not None  # checked by URLconf
     if post_reset_redirect is None:
         post_reset_redirect = reverse('django.contrib.auth.views.password_reset_complete')
     try:
@@ -221,6 +227,7 @@ def password_reset_confirm(request, uidb36=None, token=None,
     return TemplateResponse(request, template_name, context,
                             current_app=current_app)
 
+
 def password_reset_complete(request,
                             template_name='registration/password_reset_complete.html',
                             current_app=None, extra_context=None):
@@ -232,6 +239,7 @@ def password_reset_complete(request,
     return TemplateResponse(request, template_name, context,
                             current_app=current_app)
 
+
 @sensitive_post_parameters()
 @csrf_protect
 @login_required
@@ -257,6 +265,7 @@ def password_change(request,
     return TemplateResponse(request, template_name, context,
                             current_app=current_app)
 
+
 @login_required
 def password_change_done(request,
                          template_name='registration/password_change_done.html',