Merge branch 'master' into fix_threads

sflphone-common/src/audio/alsa/alsalayer.cpp

sflphone-common/src/audio/audiolayer.cpp

sflphone-common/src/audio/audiolayer.h

sflphone-common/src/audio/audiortp/AudioRtpRecordHandler.cpp

sflphone-common/src/audio/audiortp/AudioRtpSession.cpp

sflphone-common/src/audio/mainbuffer.cpp

sflphone-common/src/audio/mainbuffer.h

sflphone-common/src/audio/pulseaudio/pulselayer.cpp

sflphone-common/src/audio/ringbuffer.cpp

sflphone-common/src/audio/ringbuffer.h

sflphone-common/src/global.h

sflphone-common/src/iax/iaxvoiplink.cpp

sflphone-common/src/iax/iaxvoiplink.h

sflphone-common/src/sip/sipcall.h

sflphone-common/src/sip/sipvoiplink.cpp

sflphone-common/test/mainbuffertest.cpp