Nested FlxGroups call update() functions in the wrong order

[moly]

In an ideal world, Flixel should call preUpdate() on all game objects, then update(), then postUpdate().

When FlxGroups are nested, this is not the case. The inner FlxGroup will call preUpdate()/update()/postUpdate() during the outer FlxGroup's update() function.

For me, this behavior causes subtle off-by-one-frame errors where objects seem to lag one frame behind.

Solution: Explicitly call preUpdate() and postUpdate() at the FlxGame level, and have those calls trickle down the FlxGroups.

// in FlxGame.as
protected function update():void
        {           
            var mark:uint = getTimer();

            //FlxG.elapsed = FlxG.timeScale*(_step/1000);
            FlxG.updateSounds();
            FlxG.updatePlugins();
            _state.preUpdate();
            _state.update();
            _state.postUpdate();
            FlxG.updateCameras();

            if(_debuggerUp)
                _debugger.perf.flixelUpdate(getTimer()-mark);
        }

// in FlxGroup.as
override public function update():void
        {
            var basic:FlxBasic;
            var i:uint = 0;
            while(i < length)
            {
                basic = members[i++] as FlxBasic;
                if((basic != null) && basic.exists && basic.active)
                {
                    basic.update();
                }
            }
        }
override public function preUpdate():void
        {
            var basic:FlxBasic;
            var i:uint = 0;
            while(i < length)
            {
                basic = members[i++] as FlxBasic;
                if((basic != null) && basic.exists && basic.active)
                {
                    basic.preUpdate();
                }
            }
        }
override public function postUpdate():void
        {
            var basic:FlxBasic;
            var i:uint = 0;
            while(i < length)
            {
                basic = members[i++] as FlxBasic;
                if((basic != null) && basic.exists && basic.active)
                {
                    basic.postUpdate();
                }
            }
        }