Case-sensitive locale comparison

Locale name comparisson should correctly compare locale in localized name and description.

For example, QLocale::system().name() returns "ru_RU" for my current locale. So, i expect that
<DisplayName xml:lang="ru_RU">blabla in russian</DisplayName>
<Description xml:lang="ru_RU">blablabla in russian</Description>
will work. But they doesn't. Instead, i should type xml:lang="ru_ru" in xml file. Either make ALL locale name comparisons case insensetive, or compare them correctly.

Also xml:lang="ru" doesn't work too.