From [Release notes] Sauna 4.6.0.13:
Technical changes
The detailed changelog is here .
Sailfish-default icons are moved from
/usr/share/themes/sailfish-default/meegotouch
to
/usr/share/themes/sailfish-default/silica
There’s now an image provider component in Silica which can be registered with custom paths. Apps don’t need to put their things in the global directory.