contentlayout: items are now properly deallocated on clear

src/widget/contentlayout.cpp

@@ -73,12 +73,14 @@ void ContentLayout::clear()
     {
         item->widget()->hide();
         item->widget()->setParent(nullptr);
+        delete item;
     }
 
     while ((item = mainContent->layout()->takeAt(0)) != 0)
     {
         item->widget()->hide();
         item->widget()->setParent(nullptr);
+        delete item;
     }
 }