Menu: Harden popup closing logic

This should avoid menu popups flickering on the
screen when moving quickly over submenu items.

Change-Id: If1d4be4e643d20be01b9ad31ef5b025c5437e761
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>
Popup Window: Privately expose popup geometry

Change-Id: I28a8edd657f02cecbd0c31965bd4085429cf4537
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>
Menu: Adding sloppy submenu navigation

Because that's how human beings operate.

[ChangeLog][QtQuickControls]Added sloppy submenu navigation
Change-Id: Ife520229f1b57a76d049bb7e72826e5f1a0cd5ad
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>