Icon: port to new Height-for-width Geometry Management
Icon: port to new Height-for-width Geometry Management

GTK3 has replaced [1] the GTK2 geometry management with Height-for-width
Geometry Management [2]. This means we need to replace size_request() methods
with get_preferred_{width,height}().

[1] http://developer.gnome.org/gtk3/3.0/ch25s02.html#id1525688
[2] http://developer.gnome.org/gtk3/3.0/GtkWidget.html#geometry-management

Signed-off-by: Benjamin Berg <fe09bc2ef2737a3258f978e26226dcbac1b3f948@sipsolutions.net>
[assembled from several patches; fixed up left-over plus sign; added
description]
Signed-off-by: Sascha Silbe <be4224c72adedf72d459320ee497e22a37089288@activitycentral.com>

samdroid-apps/sugar-toolkit-gtk3,ceibal-tatu/sugar-toolkit-gtk3,Daksh/sugar-toolkit-gtk3,sugarlabs/sugar-toolkit-gtk3,manuq/sugar-toolkit-gtk3,puneetgkaur/backup_sugar_sugartoolkit,puneetgkaur/backup_sugar_sugartoolkit,tchx84/debian-pkg-sugar-toolkit-gtk3,i5o/sugar-toolkit-gtk3,Daksh/sugar-toolkit-gtk3,tchx84/debian-pkg-sugar-toolkit-gtk3,godiard/sugar-toolkit-gtk3,gusDuarte/sugar-toolkit-gtk3,sugarlabs/sugar-toolkit-gtk3,manuq/sugar-toolkit-gtk3,tchx84/sugar-toolkit-gtk3,samdroid-apps/sugar-toolkit-gtk3,tchx84/sugar-toolkit-gtk3,ceibal-tatu/sugar-toolkit-gtk3,puneetgkaur/sugar-toolkit-gtk3,quozl/sugar-toolkit-gtk3,manuq/sugar-toolkit-gtk3,ceibal-tatu/sugar-toolkit-gtk3,Daksh/sugar-toolkit-gtk3,puneetgkaur/sugar-toolkit-gtk3,puneetgkaur/backup_sugar_sugartoolkit,quozl/sugar-toolkit-gtk3,i5o/sugar-toolkit-gtk3,gusDuarte/sugar-toolkit-gtk3,gusDuarte/sugar-toolkit-gtk3,tchx84/debian-pkg-sugar-toolkit-gtk3,i5o/sugar-toolkit-gtk3,quozl/sugar-toolkit-gtk3,samdroid-apps/sugar-toolkit-gtk3,godiard/sugar-toolkit-gtk3,tchx84/sugar-toolkit-gtk3,sugarlabs/sugar-toolkit-gtk3,godiard/sugar-toolkit-gtk3,puneetgkaur/sugar-toolkit-gtk3,samdroid-apps/sugar-toolkit-gtk3,gusDuarte/sugar-toolkit-gtk3,i5o/sugar-toolkit-gtk3,quozl/sugar-toolkit-gtk3