Fixed #5786: relaxed the validation for usernames to allow more common characters '@', etc.

This is really just a stop-gap until we come up with a improved way of handling
disparate auth data, but it should help us stretch a bit more milage out of the
current system.

Thanks to alextreme, lbruno, and clayg.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12634 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/releases/1.2.txt

@@ -742,3 +742,10 @@ views in your :ref:`URLconf <topics-http-urls>`. This means that you can
 maintain complete control over the URL structure of your feeds. Like any other view, feeds views are passed a ``request`` object, so you can
 do anything you would normally do with a view, like user based access control,
 or making a feed a named URL.
+
+Relaxed requirements for usernames
+----------------------------------
+
+The built-in :class:`~django.contrib.auth.models.User` model's
+:attr:`~django.contrib.auth.models.User.username` field now allows a wider range
+of characters, including ``@``, ``+``, ``.`` and ``-`` characters.

docs/topics/auth.txt

@@ -71,6 +71,9 @@ Fields
 
         Required. 30 characters or fewer. Alphanumeric characters only
         (letters, digits and underscores).
+        
+        .. versionchanged:: 1.2
+           Usernames may now contain ``@``, ``+``, ``.`` and ``-`` characters.
 
     .. attribute:: models.User.first_name