#52 Let user know of page disconnection

Originally at 2015-02-09T12:31:25Z by Herbert Vojčík closed at 2015-02-19T09:07:25Z Until #45 is properly fixed, Helios should at least detect the page it manages has gone / reloaded / is disconnected. Otherwise, people happily develop on and then end up with "Helios is crap, it cannot commit because it some problems with namespace", though it is in fact result of the governing page disconnection instead.