Let's stop french manager doc translation

Hi all, I think we should stop french doc translation:

1. it needs a lot of job and we have no time to do it (less than 30% translated today…)
2. this doc isn't online
3. administrators of this type of software are used to reading English documentation
4. OmegaT isn't easy to use
5. I haven't found better software to translate plain HTML

@clement_oudot, @maudoux : Please send your advice below