Fix dots showing up in second column of the widget.

Since we use a two column model/treeview we need to prevent returning
some text data, otherwise we will see dots in the secound column. We also
need to emit pagesChanged once we init the model.

src/plugins/help/openpageswidget.cpp

@@ -98,7 +98,7 @@ OpenPagesWidget::OpenPagesWidget(OpenPagesModel *model)
     header()->setStretchLastSection(false);
     header()->setResizeMode(0, QHeaderView::Stretch);
     header()->setResizeMode(1, QHeaderView::Fixed);
-    header()->resizeSection(1, 16);
+    header()->resizeSection(1, 18);
 
     installEventFilter(this);
     setUniformRowHeights(true);