merge
Merge branch 'master' of https://github.com/worklist/hifi
Merge branch 'master' of https://github.com/worklist/hifi
Merge branch 'master' of https://github.com/worklist/hifi
Merge branch 'master' of https://github.com/worklist/hifi
#19426 - Add a mute control to the interface

- OpenGL overlay icon
- mute control
- icons
remove unused resource
Merge branch 'master' of https://github.com/worklist/hifi
initial stub of data server client code in Interface
stubbing of mechanism to confirm packets sent to data server
add UUID helper class to get UUID string without braces
pack string representation of UUID for data server communication
link mesh URL and UUID in prefs to data server client
#19434 restore window position on start

- store position and size on app end
- restore position and size on app start
store username and not UUID for MyAvatar
set username instead of UUID in Interface preferences
ask for a mesh if username is present on login or is changed
shore up receipt of face mesh URL from data-server
clear the face model URL if the username is changed in preferences
Progress towards a spring-mass model.