And switch Zeek's base scripts over to using it in place of
"connection_state_remove". The difference between the two is
that "connection_state_remove" is raised for all events while
"successful_connection_remove" excludes TCP connections that were never
established (just SYN packets). There can be performance benefits
to this change for some use-cases.
There's also a new event called ``connection_successful`` and a new
``connection`` record field named "successful" to help indicate this new
property of connections.
The type of the field also changed from "addr" to "string" because the
former cannot represent all possible values of the
Tunnel-Client-Endpoint attribute, which may include FQDNs, not just IP
addresses.
