Show call to action on logged user button to log out

[jenkin]

Describe the bug Login button on the top left corner contains a simple call to action (cta): log in (with entering icon).

After the authentication the same button contains username (so, no more cta) and only an icon (the exiting one) to describe the click effect: log out.

Maybe you can separate the elements (after login, the username and an independent log out button) or add a tooltip (ie. a simple title attribute) with the cta (log out).

[and0111]

@jenkin @giux78 What about this?

or this?

[jenkin]

Ok, va bene... :)