Add imports for ugettext_lazy in documentation

[anonymous]

It shouldn't say:

_("This writer's name is too long.")

it should say:

("This writer's name is too long.")

(in other words, it shouldn't have the underscore)

The code below was taken from: ​https://docs.djangoproject.com/en/1.6/topics/forms/modelforms/#overriding-the-default-fields

class AuthorForm(ModelForm):
    class Meta:
        model = Author
        fields = ('name', 'title', 'birth_date')
        labels = {
            'name': _('Writer'),
        }
        help_texts = {
            'name': _('Some useful help text.'),
        }
        error_messages = {
            'name': {
                'max_length': _("This writer's name is too long."),
            },
        }

[Tim Graham]

Actually the code is correct, but we could add the following import to help clarify: from django.utils.translation import ugettext_lazy as _

[Daniele Procida]

Ear-marked as suitable for a first-time committer at the DjangoCon Europe sprints 2014.

[niclas.ahden]

I made this change during the sprints at DjangoCon EU 2014.

Pull request posted at:

​https://github.com/django/django/pull/2663

[Tim Graham <timograham@…>]

In 7271f5db78f7c369f5dba1c0013b5eff584114df:

Fixed #22622 -- Added ugettext_lazy import in docs

[Tim Graham <timograham@…>]

In 1a3371d1e41dba8d49246e6fab1bdf5b2b236d1c:

[1.6.x] Fixed #22622 -- Added ugettext_lazy import in docs

Backport of 7271f5db78 from master