3.22, 3.24: Add gtk-mac-integration

For now added only to 3.22 and 3.24. The modules that use this are,
according to code search: glade, gspell, gedit, goffice, and gimp. It's
also used by dia but I didn't change that as dia is still on GTK 2.

https://bugzilla.gnome.org/show_bug.cgi?id=774453