Clear notification when connected to Internet

[ylogx]

Having the notification lying around when the user is clearly connected to Internet is useless and intrusive.
Desired Result:
The notification disappears after sometime when the user is logged in and appears back on when user gets disconnected.

Current Situation:
The notification stays forever once connected to a loginable network.

We should poll in the service at 5 minute intervals, ping some server (Google probably) and check if we're connected to Internet. If true, clear notification, else if false check if we need to show notification.

[ylogx]

The current situation has changed now since last two release.
On v0.6.2 the notification is only sent in once when WiFi starts up. But it will be still cooler if we could remove it when user is logged in and show it back when user gets logged out.