I finally translated all the new english strings.xml in french.
You can download it here until butchabay maybe includes it in a future release
http://www.mediafire.com/?wumcg0rxr2rk0p8
This one must be copied in Addons/skin.cirrus extended/language/French/
I read it a lot of times so there shouldn't be mistakes. The only field I couldn't really test is the PVR section because I don't have it. So I translated PVR blindly, I hope it will fit with reality. There are still some words in english because I didn't find where to translate them, but I would say 95% of the skin is now in french (compared to 30 or 40% before)
In a past post, I already complained that in Cirrus Extended submenus in the home screen, a lot of french words had bad accentuated minus caracters.
There is a problem with Cirrus Extended 2 skin, some words (strings) are not linked to the skin's strings.xml file, so the skin fetches words directly in the XBMC default french strings.xml file (and other words in the settings keep in english, I don't know where the skin fetches them)
For the Home's submenus I could identify some of these in XBMC default french strings.xml.
After reading the devWiki, I thought that copying missing strings from the XBMC strings.xml to the skin's strings.xml would work, but it doesn't, I don't know why (you can see which strings ids in the new french CirrusExtended french strings.xml posted above, right in the beginning of the file).
Desperated I made a workaround, but careful, it's nasty and will be classy only with Cirrus: I edited directly the XBMC french strings.xml, forcing caps accentuated caracters. I will give you the link to the edited strings.xml, but please make a backup of the original file before using mine, in case you choose an other skin later. I am sure there is a way to add these strings ids to the skin's language file - it would be more simple to centralize all there - but well, I am absolutely not a programmer and for me spending hours trying to understand how code works is absolutely no fun.
Here is the link for the nasty XBMC language file:
http://www.mediafire.com/?fepzxtufxyznhlm
Now I'm dead, I go to sleep
Looking forward to see Federer crushing the monkey french player Monfils tomorrow