sound: add global stopAudio to stop recording
sound: add global stopAudio to stop recording

the-impossible-quiz-revisited/the-impossible-quiz-revisited.github.io,fmateoc/SqueakJS,bertfreudenberg/SqueakJS,Speed-Pad/online,Speed-Pad/online,bertfreudenberg/SqueakJS,fmateoc/SqueakJS,the-impossible-quiz-revisited/the-impossible-quiz-revisited.github.io,fniephaus/SqueakJS,sebastianconcept/SqueakJS,fniephaus/SqueakJS,fniephaus/SqueakJS,fmateoc/SqueakJS,Speed-Pad/online,fniephaus/SqueakJS,bertfreudenberg/SqueakJS,sebastianconcept/SqueakJS,sebastianconcept/SqueakJS,the-impossible-quiz-revisited/the-impossible-quiz-revisited.github.io,bertfreudenberg/SqueakJS,the-impossible-quiz-revisited/the-impossible-quiz-revisited.github.io,fmateoc/SqueakJS