* Add exe launchers to glib2 to fix the upgrade naming conflict as pacman
can't see the difference between the new Python script without extension
and the old .exe file.
* Also add exe laucnhers for gobject-introspection so that meson can execute them.
The scripts currently have a broken shebang including an absolute path
(also the case on Linux), and fixing that would at least work for meson as it has
a shebang parser. But the exe launcher seems less error prone and also works
with other tools.
* The last update to json-glib disabled introspection due to the above mentioned
bug. This reenables it and also enables gtk-doc building while at it.
(first package fully build using only mingw tools \o/)
