dwhinham/mt32-pi v0.13.0 on GitHub

Ability to reverse global left and right audio channels (new configuration file option) to work around broken hardware (issue #307).
Support for CP2104 (and possibly other members of CP210x family) USB serial devices (issue #305). Thanks to @gritd and @ajhuitsing for reporting/finding a solution!
- This is currently achieved by applying a temporary patch to Circle to remove a part number check in the CP2102 driver.

Update to circle-stdlib v16/Circle Step 45.1.
Update ARM toolchains to 11.3.rel1.
Update to libmt32emu v2.7.0.
Update to FluidSynth v2.3.1.
Update to inih r56.
Volume up/down buttons in the simple_buttons control scheme now repeat and accelerate when pressed and held (issue #323).
Updater: config.txt is now replaced on update, however the avoid_warnings setting is preserved (the only setting that matters to most users).
Updater: improved error handling.
Installer: less often-selected Wi-Fi countries have been moved to a separate list.

Incorrect I²C clock speed with recent Raspberry Pi firmware versions (issue #292). This was caused by core clock frequency scaling by the GPU firmware. Changes to config.txt have been added to ensure the I²C clock is stable by locking the core frequency to 250MHz. The newer Raspberry Pi firmware has been restored.
Some USB MIDI controllers which make use of interrupt endpoints would not be usable (e.g. some Novation models).
Installer: invalid Wi-Fi countries removed from list according to driver source.
Installer: if using a wpa_supplicant.conf copied from a MiSTer system, invalid lines are now removed (e.g. "ctrl_interface") as they will fail under mt32-pi.