lots changes:

- renamed scene files
- fixed options back using scene.Prev
- fixed initial zooming (finally)
- fixed reset zoom (key r)
- fixed initial size, now works with state loading as well

game.go

@@ -53,6 +53,7 @@ func (game *Game) Update() error {
 
 	next := scene.GetNext()
 	if next != game.CurrentScene {
+		game.Scenes[next].SetPrevious(game.CurrentScene)
 		scene.ResetNext()
 		game.CurrentScene = next
 	}