Audio Source/End Point: event triggered if the current device is stopped while in use
Details:
SDL2AudioSource: check if device is not "stopped" while grabbing audio stream (for example if the device is unplugged). If it's the case the event OnAudioSourceError is triggered
SDL2AudioEndPoint: check if device is not "stopped" while playing back audio stream (for example if the device is unplugged). If it's the case the event OnAudioSinkError is triggered
SDL2Helper: Add new methods: IsDeviceStopped, IsDevicePlaying, IsDevicePaused, GetQueuedAudioSize, DequeueAudio and Delay