These are all nice but only workarounds. For those who wondered what tool is supposed to provide such notifications...
GNOME notification system includes between others an "update plugin", which supposed to do the job. As it does it (and quite nicely) in openSUSE GNOME 16. However it does not in Jessie GNOME 14 yet. It is not exactly a bug but rather a "not completely ready yet feature" at the release time. Here it was suggested that it should have been arrived to Jessie by now: http://blog.tenstral.net/2015/09/update-notifications-in-debian- jessie.html Looks it is not here yet. Well, as I can see, all of us have our own way to survive such a "calamity". :-) I feel much better knowing I'm not alone having the little problem. ;-) Thanks to all responded.
