MINOR: Implements new log format of option tcplog clf
Some systems require log formats in the CLF format and that meant that I
could not send my logs for proxies in mode tcp to those servers. This
implements a format that uses log variables that are compatble with TCP
mode frontends and replaces traditional HTTP values in the CLF format
to make them stand out. Instead of logging method and URI like this
"GET /example HTTP/1.1" it will log "TCP " and for a response code I
used "000" so it would be easy to separate from legitimate HTTP
traffic. Now your log servers that require a CLF format can see the
timings for TCP traffic as well as HTTP.