Major changes:
Run 4 build configurations in parallel with Valgrind on Linux
Add test failure detection verification (meta-test)
Port allocation per build to prevent conflicts in parallel runs
Add --coverage-only flag for dedicated coverage builds
Code quality:
Add TEST_GROUPS constant, CMOCKA patterns, helper functions
Organize ci-build.sh into sections
- Add prof.supp with pthread TLS suppressions
- Update ci-build.sh with test configurations
- Document functional test best practices in CONTRIBUTING.md
* Also pass `$*` to `configure` when invoking `ci-build.sh`, so one can
e.g. run `./ci-build.sh --without-xscreensaver`
Signed-off-by: Steffen Jaeckel <s@jaeckel.eu>