daemon: cleanup useless code

src/iax/iaxcall.h

src/iax/iaxvoiplink.h

src/media/audio/codecs/Makefile.am

src/media/audio/codecs/README

src/media/audio/codecs/alaw.cpp

src/media/audio/codecs/audiocodec.cpp

src/media/audio/codecs/audiocodec.h

src/media/audio/codecs/g711.h

src/media/audio/codecs/g722.cpp

src/media/audio/codecs/g722.h

src/media/audio/codecs/g729.cpp

src/media/audio/codecs/g729.h

src/media/audio/codecs/gsmcodec.cpp

src/media/audio/codecs/ilbc.cpp

src/media/audio/codecs/opuscodec.cpp

src/media/audio/codecs/opuscodec.h

src/media/audio/codecs/speexcodec.cpp

src/media/audio/codecs/speexcodec.h

src/media/audio/codecs/ulaw.cpp