soundtrack menu:
-added random options to the Custom soundtrack setting
-fixed mega satan music not being customizable in the Custom soundtrack setting
-fixed music sometimes cutting out while changing custom tracks
-fixed music not restarting in treasure rooms if the default room intro track was played as a result of the current soundtrack not having an intro set
-fixed wrong track sometimes being played when changing to custom mode
-fixed default track sometimes being incorrectly played when starting a new run after opening the game

fixed typo in music.xml preventing antibirth ultragreed music from playing

soundtrack menu:
fixed floor music not starting after treasure room intro

added song to soundtrack menu

soundtrack menu updates:
fixed angel and devil room jingles not playing
added function for custom mega satan music separate from regular satan music

added song to soundtrack menu

fixed bug in custom starting items

soundtrack menu updates:
fixed some songs not loading/playing
added some songs