I suggest add a menubutton property to automatically show the menu when mouse enter button, default true, because sometimes i want to show the menu only on button click event. Something like 'showOnMouseEnter' property:
.bind("mouseenter.menubutton", function() {
// - BEGIN EDIT
if (!opts.showOnMouseEnter) return false;
// - END EDIT
_3ea = setTimeout(function() {
_3eb(_3e8);
}, opts.duration);
return false;
})