[1.3.X] Fixed the localization docs a little to point to the correct Transifex...

[1.3.X] Fixed the localization docs a little to point to the correct Transifex URL. Also reworded it a bit to follow the site's new UI.

Backport from trunk (r17690).

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.3.X@17691 bcc190cf-cafb-0310-a4f2-bffc1f526a37