GtkRange: disconnect signals in the accessible
GtkRange: disconnect signals in the accessible

We were only disconnecting the signal in finalize, when
the widget was already unset. Instead, override the widget_set
and widget_unset vfuncs of GtkAccessible, and keep a reference
to the adjustment.

https://bugzilla.gnome.org/show_bug.cgi?id=705692

davidgumberg/gtk,ebassi/gtk,msteinert/gtk,davidgumberg/gtk,Lyude/gtk-,jigpu/gtk,Sidnioulz/SandboxGtk,chergert/gtk,chergert/gtk,Adamovskiy/gtk,grubersjoe/adwaita,davidgumberg/gtk,msteinert/gtk,jigpu/gtk,Sidnioulz/SandboxGtk,jessevdk/gtk,alexlarsson/gtk,grubersjoe/adwaita,Sidnioulz/SandboxGtk,jadahl/gtk,ahodesuka/gtk,Adamovskiy/gtk,chergert/gtk,alexlarsson/gtk,Adamovskiy/gtk,Adamovskiy/gtk,davidgumberg/gtk,ebassi/gtk,grubersjoe/adwaita,alexlarsson/gtk,jessevdk/gtk,alexlarsson/gtk,ahodesuka/gtk,Lyude/gtk-,jigpu/gtk,Lyude/gtk-,jessevdk/gtk,jadahl/gtk,Lyude/gtk-,davidgumberg/gtk,jigpu/gtk,Adamovskiy/gtk,chergert/gtk,ebassi/gtk,davidgumberg/gtk,alexlarsson/gtk,jadahl/gtk,jigpu/gtk,grubersjoe/adwaita,Lyude/gtk-,msteinert/gtk,jadahl/gtk,Adamovskiy/gtk,jessevdk/gtk,msteinert/gtk,jadahl/gtk,Adamovskiy/gtk,davidgumberg/gtk,ebassi/gtk,chergert/gtk,Sidnioulz/SandboxGtk,ahodesuka/gtk,ahodesuka/gtk,chergert/gtk,jigpu/gtk,Adamovskiy/gtk,jadahl/gtk,msteinert/gtk,Lyude/gtk-,alexlarsson/gtk,jigpu/gtk,grubersjoe/adwaita,jadahl/gtk,grubersjoe/adwaita,Lyude/gtk-,grubersjoe/adwaita,grubersjoe/adwaita,davidgumberg/gtk,alexlarsson/gtk,ebassi/gtk,Lyude/gtk-,msteinert/gtk,ahodesuka/gtk,jadahl/gtk,jigpu/gtk,chergert/gtk,jessevdk/gtk,ahodesuka/gtk,chergert/gtk,Sidnioulz/SandboxGtk,ahodesuka/gtk,alexlarsson/gtk,jessevdk/gtk,ebassi/gtk,ahodesuka/gtk,Sidnioulz/SandboxGtk,jessevdk/gtk