Bug 907330 - confirm notice handle short form of language

If user has selected 'pt', and our newsletters only list 'pt-BR' as a
supported language, that should work.
Merge pull request #83 from dpoirier/bug-907330-standard-confirmation-messages

Bug 907330 - confirm notice handle short form of language
Bug 916555: Update basket-lib.
Bug 875369 - Retry failed tasks from the admin