When logging in or out the size of the login button would not correctly update,
resulting in a messed-up flow of toolbar buttons. This branch fixes the problem
by avoiding an invalidation-chain-breaking override of Size. Instead, the loginOverlay
bypasses auto sizing by using a new framework feature.
I had earlier thought that removing this would solve the weirdness with
starting the beatmap on any but the first difficulty, and forgot to
replace it when I found the actual cause.