- sync build-dir/source-dir header path order with autotools, by
including build-dir first, then source-dir.
This prevents out-of-tree builds breaking due to leftover generated
headers in the source tree.
- tests/unit: move `src` ahead of `libtest` in header path, syncing with
autotools.
- stop adding non-existing generated `include` dir to header path.
There are no generated `include` headers and this directory is either
missing in out-of-tree builds or the same as the one already added
globally via the root `CMakeLists.txt`.
- lib: stop adding a duplicate source include directory to the header
path.
It's already added globally via the root `CMakeLists.txt`.
- lib: stop adding the project root to the header path.
- docs/examples: drop internal header paths.
Examples do not and should not use internal headers.
- replace `curl_setup_once.h` in comments with `curl_setup.h`,
the header actually used, and also referred to in autotools comments.
- add comment why we need `src` in include path for `tests/server`.
- add quotes around header directories.
Closes#14416
c6fb9895b6