Tango System Software Update icon

"Software update" icon from <a href="http://tango.freedesktop.org/Tango_Desktop_Project"> Tango Project </a> \n<br><br> \nSince version 0.8.90 Tango Project icons are Public Domain: <a href="http://tango.freedesktop.org/Frequently_Asked_Questions#Terms_of_Use.3F"> Tango Project FAQ </a>