int tls_query_connection_state(object ob)
tls_query_connection_state() returns a positive number if <ob>'s
connection is TLS secured, 0 if it's unsecured, and a negative number
if the TLS connection setup is still being set-up.
Introduced in LDMud 3.3.474 and following, backported to 3.2.11.
tls_init_connection(E), tls_deinit_connection(E), tls_error(E),