reimplements oscilloscope and connects output channels
Merge branch 'master' of git://github.com/worklist/hifi into 19165
adjusts main.cpp (oscilloscope does not render when disabled and does no longer need an external check)
Merge branch 'master' of git://github.com/worklist/hifi into 19165

Conflicts:
	interface/src/Audio.cpp
Merge pull request #157 from tschw/19165

19165