[1.2.X] Fixed #15157 -- Modified evaluation of literals surrounded by '_(' and...

[1.2.X] Fixed #15157 -- Modified evaluation of literals surrounded by '_(' and ')' in templates to be done at render time instead of at compile time by using ugettext_lazy. Thanks Jonathan S for the report.

Backport of [15327] from trunk

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@15328 bcc190cf-cafb-0310-a4f2-bffc1f526a37