Menu: Restore _destroy - remove tabIndex (gets added), don't remove ID

(can get generated, but removing only generated ideas hopefully isn't
necessary). May have to fix that later.

Author: jzaefferer

ui/jquery.ui.menu.js

@@ -177,7 +177,7 @@ $.widget("ui.menu", {
 			.andSelf()
 			.removeClass( "ui-menu ui-widget ui-widget-content ui-corner-all" )
 			.removeAttr( "role" )
-			.removeAttr("id")
+			.removeAttr("tabIndex")
 			.removeAttr( "aria-labelledby" )
 			.removeAttr( "aria-expanded" )
 			.removeAttr( "aria-hidden" )