French language corrections and additions.

Corrected french entries in grammar, spelling and accuracy.
Added those missing.
Several accents in it.

Reference, official french army doc:
http://11rdp.fr/rdp/docs/fr/Sauvetage-au-Combat--janvier-2012.pdf

Note: "vous" (Sie) is quite formal and thus I used "tu" (Du) which is more "user friendly" instead.
Merge pull request #876 from 11RDP-LoupVert/patch-4

French language corrections and additions.