audioloop: convert to AVFrame, support floating point audio

src/manager.cpp

src/media/audio/audiolayer.cpp

src/media/audio/audiolayer.h

src/media/audio/audioloop.cpp

src/media/audio/audioloop.h

src/media/audio/sound/audiofile.cpp

src/media/audio/sound/audiofile.h

src/media/audio/sound/dtmf.cpp

src/media/audio/sound/dtmf.h

src/media/audio/sound/dtmfgenerator.cpp

src/media/audio/sound/dtmfgenerator.h

src/media/audio/sound/tone.cpp

src/media/audio/sound/tone.h

src/media/audio/sound/tonelist.cpp

src/media/audio/sound/tonelist.h

src/media/audio/tonecontrol.cpp

src/media/audio/tonecontrol.h