Major changes to sound.c:
- add mutex (fixes segfault, free erros)
- allow only one sound at a time, wait for previous to finish
- outsource init function
- add global variables
- return if successfully played
currently plays sound when snake crashes (leaderboard shown)
- shorten example audio file
- Add sound.c: abstract function to play .wav files
- config:
- Add config option RENDER_GAME_TO_CONSOLE
- disable debug output
