Fix memory leak on widget destruction after certain style method accesses

This resolves Bug 1674

src/kernel/qwidget.cpp

@@ -1209,6 +1209,7 @@ void QWidget::createExtra()
 void QWidget::deleteExtra()
 {
     if ( extra ) {				// if exists
+	delete extra->m_ceData;
 	delete extra->bg_pix;
 #ifndef QT_NO_CURSOR
 	delete extra->curs;