initial hooks for stereo audio
tweak resample to handle 48 to 24 stereo, add stereo/mono byte
complete piping of stereo audio through mixer
fix input loudness for a stereo source
resolve conflicts on merge with upstream master
Merge pull request #2995 from birarda/master

initial pass at stereo input source
Merge branch 'master' of https://github.com/highfidelity/hifi into metavoxels