3.5.1 revert

BUILDING.md

CMakeLists.txt

CONTRIBUTING.md

README.md

cmake-proxies/cmake-modules/AudacityFunctions.cmake

cmake-proxies/libscorealign/CMakeLists.txt

cmake-proxies/libsoxr/CMakeLists.txt

images/CMakeLists.txt

lib-src/libnyquist/CMakeLists.txt

lib-src/portmixer/CMakeLists.txt

libraries/CMakeLists.txt

libraries/image-compiler/CMakeLists.txt

libraries/image-compiler/imageCompilerMain.cpp

libraries/lib-audio-devices/CMakeLists.txt

libraries/lib-audio-devices/DeviceManager.cpp

libraries/lib-audio-io/AudioIO.cpp

libraries/lib-audio-io/AudioIO.h

libraries/lib-audio-unit/AudioUnitWrapper.h

libraries/lib-audio-unit/CMakeLists.txt

libraries/lib-basic-ui/BasicUI.cpp