Fix problem with the filemanagement profile creating the sidebar -inside- the tabwidget instead of outside (you could see the difference when doing "add tab" :).

This is because I removed some harmful magic from the kde3 code some time ago (I'm pretty sure it created surprises in profiles with splitters and no tabs, only the current view would be converted to a tab container...).

We now never "convert to a tab container", we create the tab container correctly in the first place.