added workaround for mods with broken challenge intros

minor tweaks

-added setting into custom mode options for track to just play the floor music
-rearranged and added a bunch of code so that rooms set to use the floor music that normally have their own music by default don't restart the floor music when entering/leaving
-replaced soundtrack list shuffle ordering function with a much more efficient logic (fisher yates shuffle) game shouldn't sometimes lock up for half a second when hitting the shuffle button anymore

updates to shuffle button code to hopefully fix bug with 'default' soundtracks and also to not waste resources shuffling things and updating the config menu if you're just on a specific set soundtrack

- fixed music breaking if you press the 'Next soundtrack' button while in a boss fight
- fixed 'Next soundtrack' button sometimes not working in randomize mode

- removed AB+ fallbacks for dogma/beast intro/death jingles
- added track for Hush phase 1
- add 'currently playing' text to custom section

you can now skip to the next soundtrack in shuffle/randomize by pressing N

-added shuffle option for track settings in custom mode
-added extra error checking

extra error checking