Added Spring class. Fixed reason why World wasn't pre and post updating (Stage didn't have an exists property).

src/core/Group.js

@@ -734,7 +734,9 @@ Phaser.Group.prototype.preUpdate = function () {
         return false;
     }
 
-    for (var i = this.children.length - 1; i >= 0; i--)
+   var i = this.children.length;
+
+    while (i--)
     {
         this.children[i].preUpdate();
     }
@@ -750,7 +752,9 @@ Phaser.Group.prototype.preUpdate = function () {
 */
 Phaser.Group.prototype.update = function () {
 
-    for (var i = this.children.length - 1; i >= 0; i--)
+    var i = this.children.length;
+
+    while (i--)
     {
         this.children[i].update();
     }
@@ -771,7 +775,9 @@ Phaser.Group.prototype.postUpdate = function () {
         this.y = this.game.camera.view.y + this.cameraOffset.y;
     }
 
-    for (var i = this.children.length - 1; i >= 0; i--)
+    var i = this.children.length;
+
+    while (i--)
     {
         this.children[i].postUpdate();
     }

src/core/Stage.js

@@ -49,6 +49,12 @@ Phaser.Stage = function (game, width, height) {
     */
     this.checkOffsetInterval = 2500;
 
+    /**
+    * @property {boolean} exists - If exists is true the Stage and all children are updated, otherwise it is skipped.
+    * @default
+    */
+    this.exists = true;
+
     /**
     * @property {number} _nextOffsetCheck - The time to run the next offset check.
     * @private

src/core/World.js

@@ -95,81 +95,6 @@ Phaser.World.prototype.setBounds = function (x, y, width, height) {
 
 }
 
-/**
-* This is called automatically after the plugins preUpdate and before the State.update.
-* Most objects have preUpdate methods and it's where initial movement and positioning is done.
-* 
-* @method Phaser.World#preUpdate
-*/
-Phaser.World.prototype.preUpdate = function () {
-    
-    this.currentRenderOrderID = 0;
-
-    var i = this.children.length;
-
-    while (i--)
-    {
-        this.children[i].preUpdate();
-    }
-
-}
-
-/**
-* This is called automatically after the State.update, but before particles or plugins update.
-* 
-* @method Phaser.World#update
-*/
-Phaser.World.prototype.update = function () {
-
-    var i = this.children.length;
-
-    while (i--)
-    {
-        this.children[i].update();
-    }
-
-}
-
-/**
-* This is called automatically before the renderer runs and after the plugins have updated.
-* In postUpdate this is where all the final physics calculatations and object positioning happens.
-* The objects are processed in the order of the display list.
-* The only exception to this is if the camera is following an object, in which case that is updated first.
-* 
-* @method Phaser.World#postUpdate
-*/
-Phaser.World.prototype.postUpdate = function () {
-
-    if (this.game.world.camera.target)
-    {
-        this.game.world.camera.target.postUpdate();
-
-        this.game.world.camera.update();
-
-        var i = this.children.length;
-
-        while (i--)
-        {
-            if (this.children[i] !== this.game.world.camera.target)
-            {
-                this.children[i].postUpdate();
-            }
-        }
-    }
-    else
-    {
-        this.game.world.camera.update();
-
-        var i = this.children.length;
-
-        while (i--)
-        {
-            this.children[i].postUpdate();
-        }
-    }
-
-}
-
 /**
 * Destroyer of worlds.
 * @method Phaser.World#destroy