If there's supposed to be a dot, then of course the translation is easy. But if a comma is used, then it's more difficult and it would be good then to possibly do it differently, because you can't assume that everywhere where you use a comma in English, the respective separator is also used in other languages. For example, in English it's possible to put a comma before "and" or "or", but in German this is very uncommon.
I've added this question to a few other questions on Mdale's discussion page.
Hmm not checked, but now. And it seems unused. Maybe doublecheck because I am not very familar with JS
Not used indeed:
mw.Firefogg.js: "fogg-installed" : "Firefogg is installed.", mw.Firefogg.js: "fogg-not-installed" : "Firefogg is not installed or not enabled.", mw.Firefogg.js: // CSS selector for the "firefogg is installed" message div mw.Firefogg.js: 'target_installed': false, mw.Firefogg.js: gM( 'fogg-for_improved_uploads' ) + ' ' : gM( 'fogg-not-installed') + ' ';