- one_source_per_region_fix no longer clobbers midi source
- allow user to override per-region fix and suggest they do so.
- fix multiple note divisor detection.
- provides an upgrade path for sessions affected by a nasty bug
present in some 5.0 - 5.3 MIDI sessions.
If testing from source, it can be run from the session_utils directory
using ./run ardour5-headless-chicken -h
uselib is no longer implicit (inherited by .use). This is still incomplete,
some uselibs for non-linux variants may be missing.
bld.is_defined("HAVE_XXX") also no longer works and will have to be
changed (I think to bld.env["HAVE_XXX"]) in countless places.
