P3: Somewhat important Description
The mainenance tool uninstalls the Qt Creator pre-release, but the settings operation wrote a QtCreator.ini into the install tree. The settings operation removes the QtCreator.ini when it does its undo operation, but all the directories leading to it are kept.
So the Tools/Preview/Qt Creator.... directories stay behind.
This is especially ugly because it looks like the Qt Creator 4.5.0-rc1.app is still installed (though it contains just empty directories).