QFileDialog: directoryEntered not emitted on go-to-parent button

Though one can argue that you maybe aren't entering a directory when you leave one it is very unlikely that a programmer only is interested in when the user enters a directory.

It seems to me that this should also be done for _q_navigateForward and _q_navigateBackward (and _q_goHome ?).

Maybe it would be better to emit the signal in setDirectory ?