Update french resources and add unit tests

Hi,
You will find a few changes :
- Added missing translations in resources
- DateHumanizeTests updated to be able to run it on a non-English computer
- Added unit tests for the French translations

All running on my France french (fr-FR) computer.

I also implements of all changes for the Belgian french resources already defined in project. Normally there is no différences for this parts, but perhaps a validation by a Belgian people is needed.

Best regards,