See the readme for an example build script for GCC and Emscripten.

Duplex can be tested with the deviceio test.

If you're a binding maintainer you will need to update to use the new
result codes.

This changes the Q value of the chain of second order low-pass filters
making up the high order filters. Previously the Q value was always set
to 0.707107 for the entire chain, but this is incorrect for Butterworth
filters when the order is greater than 2.

This should make a small improvement to the quality of the linear
resampler.

This is in preparation for improving ma_lpf, ma_hpf and ma_bpf to make
them proper Butterworth filters.