* CI-unixish.yml: handle precompiled headers with `ccache`
* actually support `ccache` in CMake < 3.17
* CI-unixish-docker.yml: split CMake build and test execution into separate steps
* findDependencies.cmake: only print message about macthcompiler being disabled when it is actually used
* CI-unixish-docker.yml: added missing `ccache` CMake options
* iwyu.yml: use debian:unstable to always get latest include-what-you-use
* cleaned up includes based on include-what-you-use
* mitigated include-what-you-use false positives
* cleaned up triage.pro and pass all triage files to selfcheck
* CI-unixish.yml: factored out redundant selfcheck flags
* CI-unixish.yml: cleaned up selfcheck suppressions and fixed warnings
* added explicit `missingInclude` checks to selfcheck to work around current issues/limitations / fixed selfcheck includes / added some unit tests for `missingInclude`
* applied the selfcheck changes to the sanitizer jobs
* only fail TSAN CI build in case of TSAN error / updated sanitizer CI build TODOs
* lib/CMakeLists.txt: removed unnecessary external include
* look up tinyxml2 include dir when using system one and specify it
* lib/CMakeLists.txt: do not treat bundled headers as system ones
* CI-unixish.yml: actually perform system tinyxml2 build on macos
* modernized some CMake invocations
* CI-unixish.yml: use `ccache` for Linux gcc CMake builds
* CI-unixish-docker.yml: use `ccache` for Linux gcc CMake builds
* CI-unixish-docker.yml: enabled CMake build with tests for more images
* CI-unixish-docker.yml: adjusted some step checks
* coverage.yml: avoid duplicated test execution
* coverage.yml: split test execution and report generation into separate steps
* coverage.yml: split software and Python package installation into separate steps
* coverage.yml: removed unnecessary `libcppunit-dev` installation - library headers are only needed when performing syntax checking
* CI-unixish-docker.yml: perform make and CMake builds in parallel
* CI-unixish-docker.yml: cleanups
* CI-unixish-docker.yml: only install necessary packages
* donate_cpu_lib.py: use `os.path.join()`
* donate-cpu: removed remaining usage of `os.chdir()`
* donate_cpu_lib.py: moved library includes code into class
* donate_cpu_lib.py: pre-compile library include regular expressions
* donate_cpu_lib.py: pre-compile some more regular expressions
* donate_cpu_lib.py: small unpack_package() cleanup and optimization
* donate_cpu_lib.py: added some information about the extracted files to unpack_package()
* donate_cpu_lib.py: bumped version
* added test_donate_cpu_lib.py
* donate_cpu_lib.py: greatly improved `LibraryIncludes.get_libraries()` performance
only scan each file once for previously undetected libraries only
* test_donate_cpu_lib.py: fix for Python 3.5
* scriptcheck.yml: added `-v` to pytest calls so we get the complete diff on assertions
* fixed `test_arguments_regression()` Python tests with additional pytest arguments
* donate_cpu_lib.py: use `subprocess.check_call()`
* test_donate_cpu_lib.py: sort results to address differences in order with Python 3.5