Added logic to unset sound.used if resume is false.

Patched JS issues, this would be thrown approximately 5 seconds after World Clear theme runs:

Unknown sound: '[object Event]' 
Uncaught TypeError: Cannot set property 'loop' of undefined 

sound.used was still running even though, resume was set to false. Added a small bit of logic that resets sound.used, if resume is false so that if(sound.used == 1) sound.addEventListener("ended", playTheme); is not run after World Clear plays. Tested on multiple other levels and seems to still work as expected.