Minor warnings fixes

* TimerBase: hxd.Timer.oldTime -> lastTimeStamp;
* UISprite: h2d.Sprite -> Object;

Author: mepsoid

haxe/ui/backend/TimerBase.hx

@@ -4,7 +4,7 @@ class TimerBase {
     static private var __timers:Array<TimerBase> = [];
 
     static public function update() {
-        var currentTime:Float = hxd.Timer.oldTime;
+        var currentTime:Float = hxd.Timer.lastTimeStamp;
         var count:Int = __timers.length;
         for (i in 0...count) {
             var timer:TimerBase = __timers[i];
@@ -27,7 +27,7 @@ class TimerBase {
 
     public function new(delay:Int, callback:Void->Void) {
         this.callback = callback;
-        _start = hxd.Timer.oldTime + delay;
+        _start = hxd.Timer.lastTimeStamp + delay;
         __timers.push(this);
     }
 

haxe/ui/backend/heaps/UISprite.hx

@@ -2,7 +2,7 @@ package haxe.ui.backend.heaps;
 
 import h2d.Graphics;
 import h2d.Interactive;
-import h2d.Sprite;
+import h2d.Object;
 import haxe.ui.util.Rectangle;
 import hxd.Cursor;
 
@@ -37,7 +37,7 @@ class UISprite extends Graphics
         return value;
     }
 
-    public function new(parent:Sprite) {
+    public function new(parent:Object) {
         super(parent);
     }