Nirbheek Chauhan authored Mar 21, 2017 and Matthias Clasen committed Jul 13, 2017

This reduces the build-time dependencies of glib to only Python 3,
Meson, and git. Git is also optional if you provide a tarball in
which the subproject directories already exist.

The Python port was done by Jussi Pakkanen on bugzilla:
https://bugzilla.gnome.org/show_bug.cgi?id=779332

This version contains some fixes from that and also changes all
instances of `@` to `\u0040` because Meson does not yet provide a
configure_file() mode that ignores unknown @MACRO@ values.