Installer improvements

[bovirus]

@techygeekshome

I fixe some issue about unbtranslated strings and string that require some changes

Thanks.

[techygeekshome]

Thanks — merging this. Moving the group descriptions and the web-site icon into CustomMessages is the right call, and the Italian wording reads better.

One line needs correcting, so I'll push it straight after the merge rather than send you round again:

english.AppWebSite=Sito web {#AppName}

That sits in the Italian block but carries the english. prefix, so it redefines the English message with the Italian text and the English installer ends up showing "Sito web PDFGeek". Changing it to italian.AppWebSite= is the whole fix.

Leaving NameAndVersion, LaunchProgram and AdditionalIcons in as you wrote them.

[bovirus]

@techygeekshome

Thansk. Sorry for error.