Make it handle requests better when logged out

[Xylon2]

Sometimes the user can be logged out "in the background" without realising.

When this has happened, and the user attempts to interact with Todefer, there is no helpful error message, just nothing happens.

There needs to be a way that the user is informed that they are logged out. Preferably also such that any text boxes are preserved rather than vanishing into the void.

[Xylon2]

There is no reason the JavaScript can't remember when it's going to become logged out. When it logs in the server can tell it when it will need to re-authenticate.

Then the JavaScript can make a popup or something when due to log back in.