GUI improvements found during #707

* logs only screen in core as default
* find top window, only use Qt::WA_TranslucentBackground on top level (Qt 5.6.1)
* correct presize when insert
* resize ATC when first station is added

src/blackgui/guiutility.cpp

@@ -339,4 +339,9 @@ namespace BlackGui
         }
         return rows;
     }
+
+    bool CGuiUtility::isTopLevelWidget(QWidget *widget)
+    {
+        return QApplication::topLevelWidgets().contains(widget);
+    }
 } // ns