Minor improvement of the desktop file and its french translation

[ghost]

No description provided.

[delroth]

Would prefer if we didn't start adding i18n in there until we have a proper plan of how to handle i18n for the 20+ other languages we support.

[neobrain]

I don't think there's a point in developing any proper plan for properly handling i18n in a file which a) uses nonstandard* translations b) will very unlikely get changed anytime soon. At least, I don't think we should block these translations, waiting for such a plan.

Hence, LGTM from my side.

(*) nonstandard in the sense that it's a translation scheme not used in our project outside of that file.

[neobrain]

Turns out Transifex does support translation of .desktop files, too. We'll need to setup our infrastructure for this first though, and I don't know how long this will take. Meanwhile, you can watch https://code.google.com/p/dolphin-emu/issues/detail?id=7455 (using the "star" button) to get updates on when translations can be submitted via Transifex.