* Add configuration for CMake build system alongside autoconf
- Add a modern CMake build system (`CMakeLists.txt`, `CMakePresets.json`) that coexists with the legacy
autoconf/Makefile build
- Shared source files (`midifile.c`, `parseabc.c`, `music_utils.c`, `parser2.c`) are compiled once via OBJECT
libraries and linked into the 8 binaries
- Three presets: `default` (Release), `debug`, `sanitize` (ASan + UBSan)
- Generates `compile_commands.json` for clangd/LSP editor support
- Install rules match the legacy Makefile (binaries, doc files, man pages)
- Pinned to `-std=gnu89` because the codebase mixes K&R `()` and ANSI typed prototypes — in C23/gnu23 (GCC 15+
default), `()` means `(void)`, making these a hard error. Note: **the existing autoconf build is also broken with
GCC 15** for the same reason
```sh
cmake --preset debug
cmake --build --preset debug
cmake --install build/debug --prefix /usr/local
Documentation
- README.md: added Building section with both autoconf and CMake instructions
- doc/readme.txt: added build instructions in the existing preamble
- doc/CHANGES: added changelog entry
Test plan
- All 3 presets configure and build with GCC 15
- Smoke test: abc2midi samples/coleraine.abc produces valid MIDI through mftext
- Sanitizer build (--preset sanitize) runs clean on sample files
- Install layout verified: 8 binaries, 10 doc files, 8 man pages in correct paths
- Build on macOS (untested, should work with AppleClang)
* Implement basic testing infrastructure
The CMake build includes a test suite covering all 8 programs:
- **Smoke tests** verify each binary runs cleanly with `-ver`.
- **Golden-file tests** run each program on a sample input and compare the
(normalized) output to a checked-in reference. Binary MIDI outputs are
piped through `mftext` to produce diffable text. Volatile lines (version
banners, dates, temporary paths) are stripped before comparison.
```sh
ctest --preset debug
ctest --preset debug -L golden
ctest --preset debug -L smoke
```
To regenerate the golden files after an intentional behavioural change,
review the diff, then commit:
```sh
cmake --build build/debug --target update-golden
git diff tests/golden/
```
* Factorize more the test CMake code
* Add -PMAR option to output `P:` information as MIDI part meta-event
* Update man page and comments
* Add the instance number of a part like `Part T-4`
This allows better tracking of parts played more than once with complex `P:`
header.
* Updated CHANGES file and added author change comments in the code
