core: change in session_joined event behavior.
core: change in session_joined event behavior.

No longer suppress the event if the session was just started.  Let a UI do that
if it matters.

Kegbot/kegbot-server,Kegbot/kegbot-server,Kegbot/kegbot-server,Kegbot/kegbot-server,Kegbot/kegbot-server