The follow-state property used to have no effect, because we used pixbufs
directly. It started to work when we switched to GIcons, but it looks
bad because the prelighted icons are too contrasted, so revert to the
previous behaviour.
https://bugzilla.gnome.org/show_bug.cgi?id=694219
So that the icon is correctly highlighted when hovered. In order to do
this, we have to stop using gtk_icon_view_set_pixbuf_column() and pack a
cell renderer manually instead.
https://bugzilla.gnome.org/show_bug.cgi?id=658910
So that it has more chances of fitting on a netbook screen. This is
done by removing the 6 pixel margin, and the 12 pixel bottom padding.
This gives us the whole panel with a height of around 550 pixels with
the default text size, which should be enough to display on a 600 pixels
high screen.
https://bugzilla.gnome.org/show_bug.cgi?id=645808
