How do I sign out? Since the coins update there is no sign in/out tab.

In the top right, next to your name, there's a drop-down menu with a Sign Out link.

When i'm at the MULTI PLAYER or SINGLE PLAYER tab i dont see the drop-down menu with a Sign Out link, at the top right, next to my name.
At the other tabs i do see it.

But you can also go to "https://www.warlight.net/LogIn" to logout.