Play O Fortuna when the immortal snail sees you

Adds O Fortuna from Carmina Burana to the ImmortalSnail when the snail can see you and/or when you can see the snail (configurable).

Config options

AudioFilePath : Lets you set a file path to the audio file you want to play (default=o_fortuna.mp3). A relative path can be set here to go a few folders back.
PlayWhenSnailSeeTargetedPlayer : Play the audio file when the snail can see the player (default=true). Can be combined with PlayWhenLookingAtSnail.
PlayWhenLookingAtSnail : Play the audio file when player can see the snail (default=false).
Distance : Play the music only when the player is looking at a certain distance of the snail (also used for snail seeing the player). (default=50)
PauseWhenNotLooking : Whether to pause the music when not looking at the snail or snail is not looking at player, or stop it and start it over again when looking again. true = Pause, false = Stop. (default=true)
MusicVolume : Configure the volume of the music (value must be between 0 and 1). (default=1)