5.0.3 (stable):

* exception: Fix linking on MinGW
  (Chun-wei Fan) Issue #45 (Rosen Penev)
  (Chun-wei Fan) Pull request #46
* headers: Drop LIBXMLPP_API from 'friend' members
  (Chun-wei Fan) Pull request #47

Meson build:
* Detect if we build from a git subtree
  (William Roy) Merge request gtkmm!72
* Don't copy files with configure_file()
  (Kjell Ahlstedt)
* Fix the evaluation of is_git_build on Windows
  (Kjell Ahlstedt) Issue gtkmm#131 (William Roy)