docs fix
TYRUS-310 - When max idle timeout is reset to 0, every received message or sent ping or pong causes an empty task to be scheduled and executed
TYRUS-311: [Client] Session.setMaxIdleTimeout in @OnOpen was overridden by container wide properties.
TYRUS-293 - Automatic heartbeat PONG
Servlet test fixes
ServletWriter - previous implementation was not synchronized correctly
ServletWriter - reusing buffer array when possible
ServletWriter - further improvements/fixes
ServletWriter - TyrusServletFilter - don't force create HttpSession.
TYRUS-293: Temporarily disabling HeartbeatTest