2.65.3: (unstable):
Distro packagers should probably not package this yet.

Tests:
* glibmm_buildfilename: Add some tests
  (Kjell Ahlstedt) Issue #71 (Kalev Lember)

Build:
* Meson build: Install generate_extra_defs.h
  (Kjell Ahlstedt) Issue #70 (Jan Alexander Steffens)