MINOR: tcp-sample: Add samples to get original info about client connection

MINOR: tcp-sample: Add samples to get original info about client connection

Because source and destination address of the client connection are now
updated at the appropriated level (connection, session or stream), original
info about the client connection are preserved.  src/src_port/src_is_local
and dst/dst_port/dst_is_local return current info about the client
connection. It is the info at the highest available level. Most of time, the
stream. Any tcp/http rules may alter this info.

To get original info, "fc_" prefix must be added. For instance
"fc_src". Here, only "tcp-request connection" rules may alter source and
destination address/port.