[cairo] Status of glitz backend

[Dominic Lachowicz]

Glitz is basically an implementation of the XRender specification
using OpenGL. It's tied to the X11 drawing model, and as such, isn't
the portable OpenGL backend you're looking for.

>  Another (unrelated to glitz) piece of weirdness is the fact that librsvg creates dependences to Gdk libraries (through the gdkpixbuf prototypes and Gerror return types) even
> though you are using Cairo as the rendering backend (when it really does not need Gdk or Glib AT ALL);

GError is a graphical-toolkit agnostic way of reporting errors in C.
It has no dependencies on GTK+ or GDK.

GdkPixbuf is a convenient library for loading and displaying images
such as PNGs and JPEGs. Such as is required by the SVG specification.
You may criticize the choice of dependency (though please note that
librsvg is a GNOME project, after all), but something like it is
certainly needed.

The fact that GdkPixbuf gets packaged as part of the GTK+ software
stack is unfortunate, as it creates a dependency on a graphical
toolkit. Patches welcome.