* Make the library modular usable.
* Switch to library requirements instead of source. As source puts extra source in install targets.
* Remove relative references to boost-root in Jamfiles.
* Add requires-b2 check to top-level build file.
* Bump B2 require to 5.2
* Change all <source> references to <library>.
* Update copyright dates.
* Move inter-lib dependencies to a project variable and into the build targets.
* Update build deps.
* Replace GHA CI with simpler working one based on alandefreitas/cpp-actions utilities.
* Move project global include to target local include.
* Only msvc gets minor version tests.
* Redo GHA CI to undo move to cpp-actions.
* Remove unavailable libstdc++ package reference.
* Adjust containers and python exe name for current context.
* Remove possibly conflicting dev env setting for xcode.
* Bump some containers for package availability.
* Remove 03 testing as dependencies no longer support it.
* Adjust job names to reflect actualy cxstd tested.
* Tweaks per @pdimov
* also drop failing clang++-libc++
So "bjam pdfinstall" will now build and install the PDF to the current directory.
This works around some problems that the previous versions had if the user did not have an FO processor installed (basically Daniel James was unable to build the HTML docs for the distribution if the pdfinstall rule was implicit).
[SVN r79492]
