MIDI 2.0 June 2023 updates and the vNext (0.5)

[atsushieno]

It had been rumored for a while, but the upadtes to the MIDI 2.0 specification docs were finally published, a few days ago. https://www.midi.org/midi-articles/details-about-midi-2-0-midi-ci-profiles-and-property-exchange

I have been bringing in those new updates to ktmidi. It is tracked at the issue #44.

So far, updates to those UmpFactory and UmpRetrieval (UmpRetriever) features are basically completed.

Changes to Midi2Music is kind of planned, but now I also wonder if we should rather bring in a refresh song file class instead. Probably we do both. Midi2Music will be updated in some incompatible way to replace existing hacks to the timestamps and SMF metadata alternatives.

UmpTranslator should also be updated to emit the new Delta Clockstamp packets instead of fake JR Timestamps (we had our own way to represent the delta time in the translator). At this moment, it is too annoying to preserve the old hacks to resort to fake JR Timestamps etc.

Anyhow, it would be a good timing to bump the version to 0.5 and introduce a handful of breaking API changes as well as removal of the deprecated API.

[atsushieno]

By the way all those breaking API changes can be found using metalava API description: https://github.com/atsushieno/ktmidi/blob/main/ktmidi/api/ktmidi-api.txt