[TIMOB-5812] iOS: Support UIMenuController

   var win = Ti.UI.createWindow({
     backgroundColor: "#fff",
   });
   
   var btn = Ti.UI.createButton({
     title: "Show menu"
   });
   
   win.add(btn);
   
   var menu = Ti.UI.iOS.createMenuPopup({
     items: ["Hello", "World"]
   });
   
   menu.addEventListener("click", function(e) {
     alert(e);
   });
   
   btn.addEventListener("click", function() {
     menu.show({
       view: btn
     });
   });
   
   setTimeout(function(){
   	Ti.API.warn("hide");
   	menu.hide();
   },5000);
   
   setInterval(function() {
   	Ti.API.warn("isVisible? " + menu.isVisible());
   },1000)
   
   win.open();