extracted superclass for BackInTime video and audio stream
extracted superclass for BackInTime video and audio stream

NikolaySuslov/LivelyKernel,LivelyKernel/LivelyKernel,LivelyKernel/LivelyKernel,NikolaySuslov/LivelyKernel,pascience/LivelyKernel,LivelyKernel/LivelyKernel,NikolaySuslov/LivelyKernel,pascience/LivelyKernel,pascience/LivelyKernel