make tweens chainable with .to

Allow successive .to calls to chain tweens, and an example using it.

examples/tweens/chained tweens.php

@@ -0,0 +1,47 @@
+<?php
+    $title = "Chained Tweens";
+    require('../head.php');
+?>
+
+<script type="text/javascript">
+
+(function () {
+
+    var game = new Phaser.Game(800, 600, Phaser.AUTO, '', { preload: preload, create: create, update: update, render: render });
+
+    var p;
+    var p2;
+
+    function preload() {
+
+        game.load.image('diamond', 'assets/sprites/diamond.png');
+
+    }
+
+    function create() {
+
+        game.stage.backgroundColor = 0x337799;
+
+        p = game.add.sprite(0, 0, 'diamond');
+
+        game.add.tween(p).to({ x: 700 }, 1000, Phaser.Easing.Linear.None, true)
+        .to({ y: 300 }, 1000, Phaser.Easing.Linear.None)
+        .to({ x: 0 }, 1000, Phaser.Easing.Linear.None)
+        .to({ y: 0 }, 1000, Phaser.Easing.Linear.None);
+    }
+
+    function update() {
+
+        // p.y = game.math.min(100, game.input.y);
+
+    }
+
+    function render() {
+    }
+
+})();
+</script>
+
+<?php
+    require('../foot.php');
+?>