The hack to start new players with full breath does
not apparently work with existing players, so players
are joining to find their breath half gone at the start
of play.
Instead, let's just hide the breath HUD entirely for the
initial half of underwater movement, and only show it
when the player is running low. This effectively hides
the fact that players are losing the top half of breath
when joining, in the common case.
Players joining and being immediately submerged in
water is an uncommon enough case that this will
probably not affect gameplay significantly.
32e30328eb