QTextStream does not respect QLocale::OmitGroupSeparator

QTextStream implementation doesn't respect QLocale's QLocale::OmitGroupSeparator. This way QTextStream outputs thounsands separators no matter what locale is in use (expect "C" locale, that's hardcoded).

There's no way to workaround this without explicitly converting number to string first (I was using QTextStream for exactly that purpose. Now i can't)