This release fixes a showstopper regression for Gtk<=3.18 users where
no notifications would be displayed (Bug #12823).
Features:
* Add support for symbolic icons
* Add two new themes: Bright and Retro
* Improvements to the existing themes
Bugs fixed:
* Fix client pointer with Gtk+ < 3.20 (Bug #12823)
* Sort the themes alphabetically in the Settings Dialog
Updated translations: Polish