This has a few advantages over the old method of simply copying headers:
- Installs proper cmake files which can be picked up by our buildsystem
- Only installs necessary headers, not all of boost
Co-authored-by: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
Boost assumes variadic templates are always available in GCC 4.4+, but
they aren't since we don't build with -std=c++11.
This applies the patch that fixed the issue in boost 1.57:
eec8085549
See also: https://svn.boost.org/trac/boost/ticket/10500
