Dynamic editor theme (WIP), read desc for more info

Spaceball has been improved, you can now hit multiple balls at a time. Fork Lifter and Karate Man need this update soon as well. No idea why I did it the way I did.

Time jumping also has been improved by pausing.

Dynamic editor themes for custom theme support, however that won't be implemented until later.

Assets/Scripts/LevelEditor/Editor.cs

@@ -4,6 +4,8 @@ using UnityEngine;
 
 using UnityEngine.UI;
 
+using Newtonsoft.Json;
+
 namespace RhythmHeavenMania.Editor
 {
     public class Editor : MonoBehaviour