Add option for automatic adding translation file (issue #67)

trans/models/project.py

@@ -43,6 +43,7 @@ DEFAULT_COMMIT_MESSAGE = (
 NEW_LANG_CHOICES = (
     ('contact', ugettext_lazy('Use contact form')),
     ('url', ugettext_lazy('Point to translation instructions URL')),
+    ('add', ugettext_lazy('Automatically add language file')),
     ('none', ugettext_lazy('No adding of language')),
 )
 MERGE_CHOICES = (