First round of settings serialization.  Setup an API to load and save different settings to the avatar data file.
Initial serialized settings:
Gyro look
Mouse look
Transmitter drives
Voxel rendering
Voxel textures
Star rendering
Atmosphere rendering
Avatar rendering
Oculus rift mode
Render stats
Frame stats
Look at vectors
Logging
Frustum debugging
View frustum offset
Camera frustum
Setup various debug options.
Documentation for #19308.
Store settings in an ordered map to allow for runtime getting and setting of settings.  Read the setting file on startup, then write on shut down.
Check how many matches were found for the given data type we're checking for.  1 for bool and float, 3 for vec3.  Return false and assign default values if this isn't true.
add --local option to avatar-mixer
Coding standard cleanup based upon ZappoMan's suggestions.
simplify avatar proximity check for 1p transition
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
test
Merge remote-tracking branch 'upstream/master'
testing avatar touch
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' of https://github.com/worklist/hifi into 19308
testing avatar touch
Merge remote-tracking branch 'upstream/master'
merge
testing avatar touch
Merge remote-tracking branch 'upstream/master'