Add new Audio Class Driver Host demos.

Fix errors in the new Audio Host mode Class Driver, which would have prevented data from being sent or received properly by the device.

Add microphone/square wave generation compile time switch to the Low Level AudioOutput Host demo.

Demos/Device/ClassDriver/AudioInput/AudioInput.c

@@ -98,7 +98,7 @@ ISR(TIMER0_COMPA_vect, ISR_BLOCK)
 {
 	uint8_t PrevEndpoint = Endpoint_GetCurrentEndpoint();
 
-	/* Check if the sample reload timer period has elapsed, and that the USB bus is ready for a new sample */
+	/* Check that the USB bus is ready for the next sample to write */
 	if (Audio_Device_IsReadyForNextSample(&Microphone_Audio_Interface))
 	{
 		int16_t AudioSample;