Gtk overrides: Add TreeModelSort.__init__(self, model)
Gtk overrides: Add TreeModelSort.__init__(self, model)

This adds "model" as a required argument to TreeModelSort
instead of it being a hidden keyword argument. This is needed
because the model property is set to construct only and the
default value of None/NULL makes the object useless anyhow.

https://bugzilla.gnome.org/show_bug.cgi?id=681477

MathieuDuponchelle/pygobject,davibe/pygobject,MathieuDuponchelle/pygobject,sfeltman/pygobject,pexip/pygobject,sfeltman/pygobject,GNOME/pygobject,GNOME/pygobject,davibe/pygobject,GNOME/pygobject,pexip/pygobject,MathieuDuponchelle/pygobject,davibe/pygobject,sfeltman/pygobject,pexip/pygobject,davibe/pygobject