I have just applied your translation update (tracked as [SPARK-1588] Update French translation - Jive Software Open Source )
You can try it out in the 679 build Install4j (this will also be included in the 2.7.1 version this summer).
I didn't go the easy way to just replace the older translation on top. Because i want to preserve the history of changes and a structure of files. So, next time i would prefer to get a diff patch file. Or at least a file with only changes to translations (whole line).
I have also skipped translations which for some reason were changed to English lines. There were also some minor fixes here and there, so it won't be 100% exact.