A coming gtk deprecation

[Matthias Clasen <matthias clasen gmail com>]

The GtkWidget size-request signal / vfunc will be removed in GTK+ 3.
It is being replaced by the height-for-width machinery. The GTK+
2.91.3 release will emit a warning at runtime when size-request is
overridden, and the release after that will drop size-request
altogether.

I have written up a section in the migration guide about this and
filed patches for many of the core desktop modules that are using
gtk3. Please take a look at those.


Matthias