Fix ticket #456 (GUI:: save only the results selected in view settings)

http://sourceforge.net/apps/trac/cppcheck/ticket/456

gui/resultstree.cpp

@@ -547,6 +547,7 @@ void ResultsTree::SaveResults(Report *report)
     for (int i = 0; i < mModel.rowCount(); i++)
     {
         QStandardItem *item = mModel.item(i, 0);
+        if (!isRowHidden(i, item->index()))
             SaveErrors(report, item);
     }