have the AudioMixer handle silent audio, send silence from Interface when gate closed
fixes to silent audio frame sending
some potential fixes to QByteArray crash
have agent optionally send silent stream flag
repair _clientSamples copying into _clientMix
Merge branch 'master' of https://github.com/highfidelity/hifi into audio-scaling
Merge pull request #2345 from birarda/master

guard around update to last heard for a NULL matching node
Merge pull request #2346 from birarda/master

scope clientMixBuffer only to AudioMixer run
Prevent audio average from becoming less than zero (thus causing sqrt to
return nan, thus making our fake blendshape coefficient nan, thus making the
jaw disappear).  Closes #2334.
Merge pull request #2347 from ey6es/master

Prevent audio average from becoming less than zero (thus causing sqrt to
Alpha is the new default.
Merge pull request #2349 from ey6es/master

Alpha is the new default.
resolve conflicts on merge with upstream master
cleanup writing of silent frame to ring buffer
Merge pull request #2350 from birarda/audio-scaling

suppress silent streams from interface and agent
fix go to orientation to not put the user sideways
reset orientation to identity with spacebar, fix orientation storing
keep storing degrees in data-web but convert on receipt
remove orientation string debug
Merge branch 'master' of https://github.com/highfidelity/hifi into orientation-fix