Signed-off-by: falkTX <falktx@falktx.com>

* CMake and Visual Studio build files ignored

* Add CMakeLists

* Replace POSIX mutex with std::mutex

* Mutex unlock return value isn't used, changed signature to void

* C++ preprocessor demands different VA_ARGS syntax

* Superfluous include directory

* Expand tuning knob range to +/-1 octave.

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Co-authored-by: yaw-man <ywmn@proton.me>
Co-authored-by: wan-may <wnmy@protonmail.com>