echo cancellation: ui, calibration, visualization
Merge branch 'master' of git://github.com/worklist/hifi into 19371
libspeexdsp-based echo cancellation (untested)
implements audio echo cancellation based on speex
Merge branch 'master' of git://github.com/worklist/hifi into 19371
comments unused variable to avoid a compiler warning
separates echo cancellation from loopback test (intermediate commit)
- separates audio system round trip time determination from echo cancellation
- changes speex parameters to more humble values
- resolves build issues by removing the speex dylibs - static ones are fine
- tightens build script
adds 'Oscilloscope::setColor' and uses it when visualizing echo cancellation
Merge branch 'master' of git://github.com/worklist/hifi into 19371

Conflicts:
	interface/CMakeLists.txt
Merge pull request #565 from tschw/19371

Code Review for Job #19371