Use ugettext_lazy instead of ugettext in contrib.localflavor

[Manuel Saelices]

There are many files in localflavor that uses ugettext for defining fields and widgets, for example:

from django.utils.translation import ugettext

class NOSocialSecurityNumber(Field):
    """
    Algorithm is documented at http://no.wikipedia.org/wiki/Personnummer
    """
    default_error_messages = {
        'invalid': ugettext(u'Enter a valid Norwegian social security number.'),
    }
...

This can produce a serious problem (in production server), because two things:

1. String translation is got in import time, for example when web server starts. This string will never change.
2. This is the most important problem: You could have error with circulars import, because gettext call will try import all applications installed on Django, but this file haven't loaded yet. I had this problem with Apache for a import cycle, because a contrib.localflavor import. This is not acceptable.

I will attach a patch for fix this problem.

[Manuel Saelices]

Patch that fixes problem.

[Russell Keith-Magee]

(In [7689]) Fixed #7554 -- Modified contrib.localflavor to make use of ugettext, rather than ugettext. Thanks to msaelices for the report and patch.