Sorting a vector of internationalised strings

[Angus Leeming]

My recent splurge of patches (for which apologies again for notposting to the 
list first) have done nothing more than internationalise the language names 
in the Character, Document and Preferences dialogs. They all do it the same 
way, so I had to split some functions off into their own files that's all.

Anyway, whilst all three dilaogs now have a combox of internationalised 
language names, the vector of names really should be sorted. These comboxes 
are all built from the info passed from the function below. The first item in 
the pair is the internationalised language name, the second is it's 
identifier used by lyx.

Could someone devise an approximate and appropriate sorting functor please? I 
realise that the exact one is pretty complex but we need something at least...

Angus

src/frontends/controllers/front_lang.C:
namespace frnt {

vector<LanguagePair> const getLanguageData()
{
        vector<LanguagePair> langs(languages.size() + 2);

        langs[0].first = N_("No change"); langs[0].second = "No change";
        langs[1].first = N_("Reset");     langs[1].second = "Reset";

        vector<string>::size_type i = 2;
        for (Languages::const_iterator cit = languages.begin();
             cit != languages.end(); ++cit) {
                langs[i].first  = cit->second.display();
                langs[i].second = cit->second.lang();
                ++i;
        }

        return langs;
}

} // namespace frnt