Add wxFont::SetFaceName for wxQT to actually force the qt "font matching algoritm" to select a proper font (if not, wxFont::SetFamily has no effect). Also note that calling wxFontBase::SetFaceName causes a segmentation fault, probably caused by the UnRef() due wxFontEnumerator::IsValidFacename returns false (EnumerateFacenames is currently not implemented)
Fix to ensure font family is enforced under wxQT (discarding facename if set, forcing qt to choose a proper font)