A collection of C extension syntax files for xlib, glib (gobject, gio),
gdk-pixbuf, gtk2 (gdk2), gtk3 (gdk3), atk, at-spi, pango, cairo, clutter, gimp,
gstreamer, dbus-glib, json-glib, libglade, gtksourceview, gnome-desktop,
libgsf, libnotify, librsvg, libunique, libwnck, gtkglext, vte, poppler, evince.
The xlib one was originally created by Hwanjin Choe (vimscript #570), the
others were generated from gtk-doc declaration lists and support
enabling/disabling of highlighting of deprecated declarations.