Fix foundation#9427 - Dropdown menu mouseout ignored

Fix foundation#9427

The hide delay of the visible dropdown is replaced by the delays of the
lastly triggered dropdown, so the hide function is never called on the
currently visible dropdown.

Remember and cancel the delay inside each element. So a visible
dropdown remember its hide delay even if several dropdown must be
hidden.

js/foundation.dropdownMenu.js

@@ -118,8 +118,8 @@ class DropdownMenu {
             hasSub = $elem.hasClass(parClass);
 
         if (hasSub) {
-          clearTimeout(_this.delay);
-          _this.delay = setTimeout(function() {
+          clearTimeout(this.delay);
+          this.delay = setTimeout(function() {
             _this._show($elem.children('.is-dropdown-submenu'));
           }, _this.options.hoverDelay);
         }
@@ -129,8 +129,8 @@ class DropdownMenu {
         if (hasSub && _this.options.autoclose) {
           if ($elem.attr('data-is-click') === 'true' && _this.options.clickOpen) { return false; }
 
-          clearTimeout(_this.delay);
-          _this.delay = setTimeout(function() {
+          clearTimeout(this.delay);
+          this.delay = setTimeout(function() {
             _this._hide($elem);
           }, _this.options.closingTime);
         }