* added CMake option `DISABLE_DMAKE` to disable `run-dmake` dependencies
* tools/CMakeLists.txt: added TODO
* use `ccache` for sanitizer builds
* aligned selfcheck between sanitizer workflows and disabled some currently unnecessary steps
* CI-unixish.yml: do not use precompiled headers with `ccache`
* Makefile: bail out if `pcre-config` is missing
* CI-unixish.yml: install `pcre` for `macos` via `brew` since it suddenly disappeared from the runner images
* 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
* 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
* runtests.sh: added strict mode - enabled via `STRICT=1`
* CI-unixish.yml: added strict cfg check
* runtests.sh: disabled syntax check for kde.cpp since `kde-4config` is no longer commonly available in recent distros
* runtests.sh: disabled syntax check for opencv2.cpp since `opencv.pc` is not commonly available in distros
* runtests.sh: added missing trailing slash to `CFG` - fixes define checks
Oliver Stöneberg
Daniel Marjamäki