QMenuPrivate: Make sloppyDelayTimer non-static

Keeping the timer static would trigger warnings when enabling
SH_Menu_SloppySubMenus in QCommonStyle in a forthcoming patch.
This would happen if we opened a second level submenu quickly
enough and get the mouse event handler to reset the timer its
parent menu started.

This is a backport of Ia768603b40b219f87138c60a595c65ef408761ae
from qt/qtbase.

Change-Id: Ia7e9a94b3445d9362a60a36d5e4dda878ab0f7a5
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
QMenu: Enable sloppy submenu mouse navigation

Since we're in the 21st century, we set QCommonStyle to return true
to the SH_Menu_SloppySubMenus style hint. This unlocks all the logic
already available in QMenu.

This is a backport of I134c87e348d98d1f46055e0bfef2b4a4a3d2993a
from qt/qtbase and includes some previous enhancements.

Task-number: QTBUG-20094
[ChangeLog][QtWidgets][QMenu] Enable sloppy submenu mouse navigation
Change-Id: If4141a3d849123850e40af92ac5aede9ed767bdf
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
QMenu: Sloppy menu selection should allow hovering separators

Setting the current action to 0 clears the sloppy region and
closes the submenu if we hover a separator on the way to the
submenu popup. Now, we choose not to while the sloppy delay
timer is running.

This is a backport of I9d1b1358fe64c259dc47f35db8fc8f2b19a73153
from qt/qtbase.

Task-number: QTBUG-20094
Change-Id: If4b3cff05a9bcb41cee3e49490d4cc5fc3595821
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>