New release: libmixed / cl-mixed v2.3 (Patreon)

I know I just had a release for these a few days ago, but since then I've implemented Vector-Based Amplitude Panning (VBAP) and massively overhauled the spatial mixer as a consequence to both support proper stereo panning as well as outputting to arbitrary speaker configurations.

I've also added several other convenience and helper functions to deal with speaker configuration and allow for better segment introspection.