Bug fixes

Bugs fixed:

Music continues between levels, rather than restarting - attached the music to a GameObject with DontDestroyOnLoad, so it doesn't get deleted when a scene ends. Checks to make sure it doesn't already exist if the scene is reloaded.

Move counter could decrement below 0 and  chair could move after moves have reached 0 - put in if statements to check for these.

"game over" screen and "end level" screen don't sometimes display on top of each other - the "game over" screen now checks to make sure the player hasn't won before spawning.