Fix z-index. Pull up z-index to MeshBase.

Assets/Cryville/Crtr/GenericResources.cs

@@ -19,6 +19,7 @@ namespace Cryville.Crtr {
 		public static void LoadDefault() {
 			if (loaded) return;
 			Components.Add("image", typeof(SpritePlane));
+			Components.Add("mesh", typeof(MeshBase));
 			Components.Add("polysec", typeof(PolygonSGO));
 			Components.Add("rect", typeof(SpriteRect));
 			Components.Add("scale3", typeof(SpriteScale3));