[arch-dev-public] icon theme caches

[Jan de Groot]

As implemented in namcap, namcap now checks for the cache updating
in /usr/share/icons/hicolor. I would like to extend this policy
to /usr/share/icons/gnome also for 2.28. At this moment only
gnome-icon-theme should be affected, but I don't know if there's other
icon themes or applications installing icons there.

# find /usr/share/icons/hicolor/ -type f | wc -l
616

# find /usr/share/icons/gnome/ -type f | wc -l
3002

Makes sense to cache gnome also then. There's some other themes
extending the gnome theme, hicolor is default always, so caching this
will make gnome applications a lot faster when doing icon lookup.