[gtk+] Created tag 3.20.6

[Matthias Clasen <matthiasc src gnome org>]

The unsigned tag '3.20.6' was created.

Tagger: Matthias Clasen <mclasen redhat com>
Date: Mon May 23 10:23:55 2016 -0400

    3.20.6

Changes since the last tag '3.20.5':

Carlos Garnacho (1):
      popover: set priv->window before setting doing add_popover() on it

Florian Müllner (1):
      stack: Only map children when necessary

Ignacio Casal Quinteiro (1):
      gtktextview: fix < public > comment

Khaled Hosny (1):
      Update Arabic translation

Lapo Calamandrei (2):
      Adwaita: shave 1px from the switch
      Adwaita: add vertical margins to switches on a headerbar

Matthias Clasen (3):
      Revert "scrolledwindow: Remove child before destroying self"
      treeview: Fix a rubberbanding-related crash
      3.20.6