icons, and other ui work

We're now compressing the notficiations when a new wireless network appears by (re-)starting a timer when a new network appears and collecting the network's essids in the meantime.
This prevents the event notification storm when you start the applet and there are existing networks found.
Much, much better this way ... :)

Also, fix lots of icons. media-playback* is semantically incorrect, use network-(dis)connect instead.
And be a lot less noisy doing all that.