Added addedToScene and removedFromScene methods

* `GameObject.addedToScene` is a new method that custom Game Objects can use to perform additional set-up when a Game Object is added to a Scene. For example, Sprite uses this to add itself to the Update List.
* `GameObject.removedFromScene` is a new method that custom Game Objects can use to perform additional tear-down when a Game Object is removed from a Scene. For example, Sprite uses this to remove themselves from the Update List.
* Game Objects no longer automatically remove themselves from the Update List during `preDestroy`. This should be handled directly in the `removedFromScene` method now.

Author: photonstorm

src/gameobjects/GameObject.js

@@ -58,9 +58,9 @@ var GameObject = new Class({
 
         /**
          * The current state of this Game Object.
-         * 
+         *
          * Phaser itself will never modify this value, although plugins may do so.
-         * 
+         *
          * Use this property to track the state of a Game Object during its lifetime. For example, it could change from
          * a state of 'moving', to 'attacking', to 'dead'. The state value should be an integer (ideally mapped to a constant
          * in your game code), or a string. These are recommended to keep it light and simple, with fast comparisons.
@@ -230,9 +230,9 @@ var GameObject = new Class({
 
     /**
      * Sets the current state of this Game Object.
-     * 
+     *
      * Phaser itself will never modify the State of a Game Object, although plugins may do so.
-     * 
+     *
      * For example, a Game Object could change from a state of 'moving', to 'attacking', to 'dead'.
      * The state value should typically be an integer (ideally mapped to a constant
      * in your game code), but could also be a string. It is recommended to keep it light and simple.
@@ -337,7 +337,7 @@ var GameObject = new Class({
      * before setting the value.
      *
      * If the key doesn't already exist in the Data Manager then it is created.
-     * 
+     *
      * When the value is first set, a `setdata` event is emitted from this Game Object.
      *
      * @method Phaser.GameObjects.GameObject#incData
@@ -367,7 +367,7 @@ var GameObject = new Class({
      * before setting the value.
      *
      * If the key doesn't already exist in the Data Manager then it is created.
-     * 
+     *
      * When the value is first set, a `setdata` event is emitted from this Game Object.
      *
      * @method Phaser.GameObjects.GameObject#toggleData
@@ -505,7 +505,7 @@ var GameObject = new Class({
      * If you wish to only temporarily stop an object from receiving input then use
      * `disableInteractive` instead, as that toggles the interactive state, where-as
      * this erases it completely.
-     * 
+     *
      * If you wish to resize a hit area, don't remove and then set it as being
      * interactive. Instead, access the hitarea object directly and resize the shape
      * being used. I.e.: `sprite.input.hitArea.setSize(width, height)` (assuming the
@@ -525,6 +525,36 @@ var GameObject = new Class({
         return this;
     },
 
+    /**
+     * This callback is invoked when this Game Object is added to a Scene.
+     *
+     * Can be overriden by custom Game Objects, but be aware of some Game Objects that
+     * will use this, such as Sprites, to add themselves into the Update List.
+     *
+     * You can also listen for the `ADDED_TO_SCENE` event from this Game Object.
+     *
+     * @method Phaser.GameObjects.GameObject#addedToScene
+     * @since 3.50.0
+     */
+    addedToScene: function ()
+    {
+    },
+
+    /**
+     * This callback is invoked when this Game Object is removed from a Scene.
+     *
+     * Can be overriden by custom Game Objects, but be aware of some Game Objects that
+     * will use this, such as Sprites, to removed themselves from the Update List.
+     *
+     * You can also listen for the `REMOVED_FROM_SCENE` event from this Game Object.
+     *
+     * @method Phaser.GameObjects.GameObject#removedFromScene
+     * @since 3.50.0
+     */
+    removedFromScene: function ()
+    {
+    },
+
     /**
      * To be overridden by custom GameObjects. Allows base objects to be used in a Pool.
      *
@@ -651,7 +681,6 @@ var GameObject = new Class({
         if (!fromScene)
         {
             sys.displayList.remove(this);
-            sys.updateList.remove(this);
         }
 
         if (this.input)