KXmlGuiWindow documentation tells us to not pass the 'Create' flag:
```
* NOTE: when using KParts::MainWindow, remove this flag from
* the
* setupGUI call, since you'll be using createGUI(part) instead.
* @code
* setupGUI(ToolBar | Keys | StatusBar | Save);
* @endcode
```
This in fact fixes a real problem. Before this patch duplicate standard
actions (e.g. the 'help' actions are created).
There's a problem, though, this changes messes up KDevelop's menu bar:
{F3069248}
This is how it looks like normally:
{F3069239}