Thanks to the post by cvidal (
3.1.1 GA 394 French Translation, I decided to go along with his suggestion. After searching a bit about the ubiquitous and problematic \u0027 (the single quote), I found that the Unicode.org proposed replacement is \u2019, which fits quite well in the typography of the GUI. All that was broken in the GUI is now fixed (filters were all messed up, I just discovered, among other things).
I replaced in the three properties files all "doubled" single quotes, and a few lonely ones with this hex, except for a few surrounding urls in HTML code snippets found in the files.
Hope this will help my fellow translators.
For people who would like a thorough translation to French of the Zimbra interface of the above release, please email me.
F.