Commit by patthoyts (branch: core-8-5-branch):
[Bug 2949774]: cascade menus should popdown ofter loosing the pointer.
When the pointer moves to another entry from a cascade entry the sub-menu
should popdown. This is how other menus on X11 work today. This effect will
not be used if the user has configured ClickToFocus to maintain the previous
Tk menu effects.
(backported from trunk)
Signed-off-by: Pat Thoyts <patthoyts@...>