Calling tport_alloc_seconary() when client socket has been created, making
it possible to set socket options before connecting the socket. Currently,
this benefits SCTP and TLS.

This change affects tport_internal.h, tport.c, tport_type_sctp.c,
tport_type_tcp.c, and tport_type_tls.c.

darcs-hash:20060426165300-65a35-6d262b339a4362e16a2b20777e1d580efff33194.gz