A line that starts with "/" is a command, a whisper or party chat, so typing
one no longer shows dots to the whole server. Dots already showing are cleared
when the line becomes one.
A "stopped typing" notice was relayed every time it arrived, while "typing"
was held to one per 200 ms, so a modified client could flood everyone through
the host. A lobby's host and a dedicated server now pass a stop on only when
that player's dots are up, which is at most once per accepted "typing".