WARNING: A destroyed FlxBasic can't be used anymore.
It may even cause crashes if it is still part of a group or state.
You may want to use kill() instead if you want to disable the object temporarily only and revive() it later.
This function is usually not called manually (Flixel calls it automatically during state switches for all add()ed objects).
Override this function to null out variables manually or call destroy() on class members if necessary.
Don't forget to call super.destroy()!