Tarball doesn't include CMake info

[rickmark]

The released tarballs do not include CMake based build data.

This makes it impossible for things like home-brew to install CMake modules therefore CMake based dependency on header only libraries such as libboost_system are broken for macOS.

There's no good reason to filter this, and there needs to be better support from b2 to install the proper CMake data for depending on non dylib/a/so based header only libraries.

I believe the best option is to have macOS use cmake based builds, but this cannot happen without the tarball including the proper data for it.

Replication Steps:

To install brew without CMake

brew install boost

Look for libboost_system in any cmake project

To test for cmake

Try and install gr-osmocom on macOS

[rickmark]

I do think this is worth a 1.89.1 tarball since this is in fact a breaking problem...