Move translations to transifex.com

Translation management is done through Transifex now for easy translations.
Translators should note that fuzzy strings are not used any more since
Transifex does not handle it (by choice).

In order to pull translations, you need a transifex.com account.

Signed-off-by: Kévin Raymond <shaiton@fedoraproject.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>