PortAudio library integration instead of alsa and oss

CHANGES

Makefile

configure

src/Makefile

src/audio/audiocodec.cpp

src/audio/audiocodec.h

src/audio/audiodrivers.h

src/audio/audiodriversalsa.cpp

src/audio/audiodriversalsa.h

src/audio/audiodriversoss.cpp

src/audio/audiodriversoss.h

src/audio/audiortp.cpp

src/audio/audiortp.h

src/audio/dtmf.cpp

src/audio/dtmf.h

src/audio/dtmfgenerator.cpp

src/audio/dtmfgenerator.h

src/audio/tonegenerator.cpp

src/audio/tonegenerator.h

src/global.h